20. Norddeutsches Doktorandenkolloquium in Kiel September 2017

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1 20. Norddeutsches Doktorandenkolloquium in Kiel September 2017

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3 Grußwort zum 20. Norddeutschen Doktorandenkolloquium Liebe Kolleginnen und Kollegen, liebe Doktorandinnen und Doktoranden, im Namen des Instituts für Anorganische Chemie der Universität Kiel möchten wir Sie alle recht herzlich willkommen heißen und freuen uns auf das diesjährige 20. Norddeutsche Doktorandenkolloquium mit Ihnen in Kiel, der Landeshauptstadt Schleswig-Holsteins. Das Ziel der Veranstaltung ist die Vernetzung und der gegenseitige Austausch unter den Doktorandinnen und Doktoranden sowie den Arbeitsgruppenleiterinnen und Arbeitsgruppenleitern aus den Arbeitsgruppen der Anorganischen Chemie und angrenzenden Fachgebieten im Verbund der Norddeutschen Universitäten. Ein produktiver Gedanken- und Ideenaustausch wird im Rahmen von Vorträgen sowie Posterpräsentationen von Doktorandinnen und Doktoranden in einer entspannten Atmosphäre ermöglicht. Seit nunmehr 20 Jahren findet das Norddeutsche Doktorandenkolloquium an den Universitäten Norddeutschlands statt. Anlässlich dieses Jubiläums freuen wir uns Prof. Dr. Biprajit Sarkar von der Freien Universität Berlin für einen Plenarvortrag begrüßen zu dürfen. Wir möchten uns ganz herzlich für die Unterstützung durch Sponsoren und Förderer bedanken, ohne deren Hilfe das 20. Norddeutsche Doktorandenkolloquium nicht möglich gewesen wäre. Weiterhin danken wir zahlreichen Helfern für deren tatkräftigen Einsatz. Wir freuen uns auf eine spannende, interessante Tagung mit anregenden Diskussionen und Gesprächen mit Ihnen allen. Herzliche Grüße, Prof. Dr. Wolfgang Bensch, Prof. Dr. Felix Tuczek, Prof. Dr. Norbert Stock und das Organisationsteam

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5 Wir bedanken uns recht herzlich bei den Firmen, Vereinen und Institutionen, die das NDDK 2017 in Kiel möglich gemacht haben. Sponsoren n Förderer 1

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7 Programm Die Veranstaltungen finden am Otto-Hahn-Platz 5, Kiel statt. Die Postersession s und Kaffeepausen finden in der Eingangshalle, die Vorträge im Hörsaal I statt. Donnerstag Freitag Registrierung 11:00 Uhr 13:00 Uhr Begrüßung und Eröffnung 13:00 Uhr 13:10 Uhr Plenarvortrag 13:10 14:00 Doktorandenvorträge I 14:00 Uhr 14:50 Uhr Kaffeepause 15:00 Uhr 15:15 Uhr Doktorandenvorträge II 15:15 Uhr 17:55 Uhr Postersession I gerade Nummern 18:00 Uhr 19:00 Uhr Grillen Ab 19:00 Uhr Postersession II ungerade Nummern 08:30 Uhr 09:30 Uhr Doktorandenvorträge III 09:30 Uhr 11:10 Uhr Kaffeepause 11:10 Uhr 11:45 Uhr Doktorandenvorträge IV 11:45 Uhr 14:05 Uhr Verabschiedung & Vergabe Präsentationspreise 14:05 Uhr 14:20 Uhr 3

8 Vorträge Donnerstag 13:10 Redox-Switchable Catalysis with 1,2,3.Click Biprajit Sarkar* Freie Universität Berlin 14:00 Electrochemical N2-splitting in the coordination sphere of Re Van Alten, R.S., Lindley, B., Schendzielorz, F., Miller, A.C.M., Siewert, I., Schneider, S* Universität Göttingen 14:20 Synthetic nitrogen fixation with mononuclear molybdenum complexes: Electronicstructural and mechanistic insights from DFT Benedikt Flöser, Felix Tuczek* Universität Kiel 14:40 Experimental Charge-Density Studies of a Donor stabilized tert-butyl-lithium Dimer Annika Münch, Dietmar Stalke* Universität Göttingen Kaffeepause 15:15 From Homogeneous to Heterogeneous Catalytic Alkyne Metathesis Celine Bittner, Matthias Tamm* TU Braunschweig 15:35 Synthese neuartiger Vanadium(IV/V)-Katalysatoren für die enantioselektive Oxidation von prochiralen Sulfiden Lina Fischer,Carola Schulzke * Universität Greifswald 15:55 Vom Alkinkomplex zum kohlenstoffbasierten FLP Helge Lange, Kai Helmdach, Alexander Villinger, Wolfram W. Seidel* Universität Rostock 16:15 Erleuchtete Wege zu Monodithiolenkomplexen des Wolframs und des Molybdäns Benedict Elvers, Christian Fischer* Universität Greifswald 16:35 In-depth Mechanistic Investigations of the Rhodium Catalyzed Propargylic CH Activation Saskia Moeller, Antje Meißner, Julia Rueger, Hans-Joachim Drexler and Detlef Heller* LIKAT Rostock 16:55 Rhenium Complexes with Proton Responsive Ligands as Redox Catalysts in the CO2 Reduction Reaction Jia-Pei Du, Alexander Wilting, Jennifer Ahrens, Dirk Schwarzer, Inke Siewert* Universität Göttingen 17:15 C H Bindungsaktivierung von Phosphoryliden an Bis(η 5 :η 1 - pentafulven)titankomplexen Generierung eines zick-zack Hexapentaene H2C=C=C=C=C=CH2 Komplexes Tim Oswald, Rüdiger Beckhaus* Universität Oldenburg 17:35 In situ spectroscopic studies of the Cu I /TEMPO mediated aerobic alcohol oxidation Sven Adomeit, Jabor Rabeah, Annette-E. Surkus, Ursula Bentrup, Angelika Brückner* LIKAT Rostock Ende: 17:55 4

9 Freitag 09:30 Concepts for the Synthesis of a Tetrazabismuthole Max Thomas, Axel Schulz*and Alexander Villinger Universität Rostock 09:50 Tetrylenes Stabilized by Homoconjugation Zhaowen Dong, Crispin R. W. Reinhold, Thomas Müller * Universität Oldenburg 10:10 Trends in Synthesis and Reactivity of Stannoles Sara Urrego-Riveros, Isabel M. Ramírez y Medina, Anne Staubitz* Universität Bremen 10:30 An iron PNP pincer complex for dehydropolymerisation of methylamine borane Felix Anke, Monica Ferro, Anke Spannenberg, Torsten Beweries* LIKAT Rostock 10:50 Tuning of Tc through mixed crystal formation in thiocyanate coordination polymers with ethylisonicotinate Tristan Neumann, Carsten Wellm and Christian Näther * Universität Kiel Kaffeepause 11:45 A supramolecular approach: artificial metalloproteases based on the oxacyclen ligand Sebastián Hinojosa, Nils Hatje, Nora Kulak* Freie Universität Berlin 12:05 Sila-Ibuprofen Florian Kleemiss, Daniel Duvinage, Patrick Watermann, Aileen Justies, Werner Reutter, Nelly Rivas King, Eric Ehrke, Jens Beckmann, Ralf Dringen, Simon Grabowsky* Universität Bremen 12:25 Seltenerdmetallkomplexe mit einem sterisch anspruchsvollen Pentadienyl-Liganden Eigenschaften und Reaktivität J. Raeder, M. Reiners, M. Freytag, P. G. Jones, M. D. Walter* TU Braunschweig 12:45 Growth and characterization of single crystalline alpha- and beta-pbalbo4 M. Gogolin, M. M. Murshed, Th. M. Gesing* Universität Bremen 13:05 Organoantimony(III)-containing Polyoxometalates: Tuning of Bioactivity by Ligand Functionalization Tian Ma and Ulrich Kortz* Jacobs University Bremen 13:25 Syntheseoptimierung von Zr-Cluster-Verbindungen Jonas Jablonski und Martin Köckerling* Universität Rostock 13:45 SynRAC A multi-purpose reaction cell for the investigation of reactions under solvothermal conditions N. Heidenreich, U. Rütt, M. Köppen, A. K. Inge, A. C. Dippel, R. Suren and N. Stock* Universität Kiel Ende: 14:05 5

10 Redox-Switchable Catalysis with 1,2,3.Click Biprajit Sarkar* Institut für Chemie und Biochemie, Freie Universität Berlin Fabeckstraße 34-36, 14195, Berlin Presentation Triazolylidenes are a prominent class of mesoionic carbenes (MICs) that are currently popular in diverse branches of chemistry.[1,2] This contribution will deal with the synthesis of such MICs and their metal complexes. Furthermore, the estimation of the donor properties of these MICs and the tuning of such properties through redox processes will be addressed. Finally, the utility of the metal complexes of MICs in a series of redox-induced and redox-switchable (electro)catalytic processes will be discussed. Specifically, the following cases will be addressed: a) the first example of a redox-switchable gold(i) catalyst,[3,4] b) the first examples of rhenium(i)-mic complexes[5] and their utility in electrocatalytic CO2 reduction, and c) the first example of a cobalt(iii)-mic complex displaying the lowest known over-potential for electrocatalytic proton reduction in organic medium.[6] [1] P. Matthews, A. Neels, M. Albrecht, J. Am. Chem. Soc., 2008, 130, [2] D. Schweinfurth, L. Hettmanczyk, L. Suntrup, B. Sarkar, Z. Anorg. Allg. Chem., 2017, 643, 554. [3] L. Hettmanczyk, L. Suntrup, S. Klenk, C. Hoyer, B. Sarkar, Chem. Eur. J. 2017, 23, 576. [4] S. Klenk, S. Rupf, L. Suntrup, M. van der Meer, B. Sarkar, Organometallics, 2017, 36, [5] L. Suntrup, S. Klenk, J. Klein, S. Sobottka, B. Sarkar, Inorg. Chem., 2017, 56, [6] M. van der Meer, E. Glais, I. Siewert, B. Sarkar, Angew. Chem. Int. Ed., 2015, 54,

11 Electrochemical N2-splitting in the coordination sphere of Re Van Alten, R.S., Lindley, B., Schendzielorz, F., Miller, A.C.M., Siewert, I., Schneider, S. Universität Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, 37077, Göttingen; University of North Carolina, Chapel Hill, NC Presentation Synthetic N2 fixation at low pressures and temperatures remains as one of the most challenging problems in catalysis.[1] In recent years, several model systems were established that enable catalytic ammonia production using alkali metal (KC8, NaHg) or organometallic (CoCp2*) reductants. Ultimately, electrochemical approaches provide an appealing alternative.[2] However, electrocatalytic N2 fixation is scarcely examined and not known with molecular catalysts. We here report a synthetic and mechanistic study on electrochemical N2 splitting from the Re-pincer complexes 1a/1b (Figure 1), that we previously established for N2 cleavage and transfer.[3,4] Electrolysis at 1 bar N2 affords the corresponding nitride complexes (2a/2b) in moderate to good yields. Cyclic voltammetry was used to elucidate the initial steps of the N2- reduction mechanism, providing valuable information for the design of electrocatalysts with high activity and selectivity. [1] Klopsch, I., Yu Yuzik-Klimova, Ekatarina, Schneider, S., Top Organomet Chem 2017, 60, [2] Garagounis, I., Kyriakou, V., Skodra, A., Vasileiou, E., Stoukides, M., Frontiers in Energy Research, 2014, 2, [3] Klopsch, I., Finger. M, Würtele, C., Milde, B., Werz, D., Schneider, S., J. Am. Chem. Soc. 2014, 136, [4] Klopsch, I., Kinauer, M., Finger, M., Würtele, C., Schneider, S., Angew. Chem. Int. Ed. 2016, 55,

12 Synthetic nitrogen fixation with mononuclear molybdenum complexes: Electronic-structural and mechanistic insights from DFT Benedikt Flöser, Felix Tuczek* Department of Inorganic Chemistry, University of Kiel Max-Eyth-Straße 2, Kiel, Germany Presentation The fixation of molecular dinitrogen from the atmosphere performed by the enzyme nitrogenase has drawn considerable interest, and although large advancements have been made towards understanding the involved processes, many questions yet remain.[1] So far various model systems for synthetic nitrogen fixation have been presented some of which exhibit catalytic ammonia formation. Recently our group identified and synthesized a promising model complex featuring a new pentadentate ligand systems that was designed to envelop the metal center completely and thus minimize spurious side reactions (cf. Fig. 1).[2] An in-depth study of this [Mo(N2)(pentaPod)] complex was conducted including spectroscopic characterization, evaluation of the activation towards protonation and an extensive DFT study of the reactive pathway leading from N2 to NH3. The latter provided a useful comparison to previously synthesized complexes and demonstrated the potential of this complex for a catalytic nitrogen fixation cycle.[3] Fig. 1: Schematic and optimized structure of the Mo(0)-N 2 pentapod complex. Hydrogen atoms are omitted for clarity. [1] S. Hinrichsen, H. Broda, C. Gradert, L. Söncksen, F. Tuczek, Annu. Rep. Prog. Chem., Sect. A: Inorg. Chem. 2012, 108, 17. [2] S. Hinrichsen, A. Kindjajev, S. Adomeit, J. Krahmer, C. Nather, F. Tuczek, Inorg. Chem. 2016, 55, [3] B. M. Flöser, F. Tuczek, Coord. Chem. Rev. 2016, 345,

13 Experimental Charge-Density Studies of a Donor stabilized tert- Butyl-Lithium Dimer Annika Münch, Dietmar Stalke* Institute for Inorganic Chemistry, Georg-August-University Göttingen Tammannstraße 4, Göttingen amuench@chemie.uni-goettingen.de Presentation Lithiumorganyls are used in versatile manner in organic as well as inorganic syntheses. They are key reagents in deprotonation reactions or for transfer of organic rests. For understanding their reactivity it is of great importance to investigate the molecular and electronic structure of reactive species. The electrondenstity is determined by high resolution x-ray experiments in solid state experimentally and examined after the quantity theory of atoms in molecules (QTAIM). For this work the crystal structure of Quinuclidin stabilized tert-butly-lithium-dimer of was examined. With the help of high resolution data the electrondensity was refined with Hansen & Coppens multipol model to determine the binding situation. Figure 1: Molecular structure of Ouinuclidin stabilized tert-butly-lithium-dimer in the solid state. Hydrogens are omitted for clarity. Anisotropic displacement parameters are depicted at the 50% probability level. [1] T. Stey, D. Stalke, The chemistry of organolithium compounds 2004, 47. [2] R. F. W. Bader, Chem. Rev. 1991, 91, 893. [3] N. K. Hansen, P. Coppens, Acta Cryst A 1978, 34,

14 From Homogeneous to Heterogeneous Catalytic Alkyne Metathesis Celine Bittner, Matthias Tamm* Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig Hagenring 30, Braunschweig Presentation Within the last decades, numerous effective metal alkylidyne complexes of the Schrock type (RC MX3) based on molybdenum or tungsten have been developed.[1,2] These complexes can serve as pre-catalysts for various alkyne metathesis reactions including more specialized reactions as the metathesis of 2,4-hexadiynes or terminal alkynes.[3,4] Recently, we were able to graft our most effective pre-catalyst [MesC Mo{OCCH3(CF3)2}3] (MoF6) onto partially dehydrated silica (SiO2-700) in order to prepare a well-defined heterogeneous alkyne metathesis pre-catalyst (MoF6/SiO2-700). Surprisingly, the immobilized system showed less activity than the molecular one which expressed very high TON and TOF5min even with catalyst loading at ppm level.[5] To investigate the origin of this reduced activity we prepared the molecular model system [MesC Mo{OCCH3(CF3)2}2{OSi(OtBu)3}] (MoF6-TBOS).[6] Besides the catalytic activity of the molecular complexes in comparison to the immobilized system MoF6 analogues featuring alkoxide ligands with varying degree of fluorination will be discussed in order to examine the electronic effect of the anxillary ligand X.[6,7] [1] Fürstner, Angew. Chem. Int. Ed. 2013, 52, [2] Wu, Tamm, Beilstein J. Org. Chem. 2011, 7, 82. [3] Lysenko, Volbeda, Jones, Tamm, Angew. Chem. Int. Ed. 2012, 51, [4] Haberlag, Freytag, Daniliuc, Jones, Tamm, Angew. Chem. Int. Ed. 2012, 51, [5] Estes, Angew. Chem. Int. Ed. 2016, 55, [6] Estes, Fedorov, Gordon, Liao, Ehrhorn, Bittner, Bockfeld, Zier, Chan, Safonova, Eisenstein, Raynaud, Tamm, Copéret, manuscript in preparation. [7] Bittner, Ehrhorn, Brandhorst, Bockfeld, Tamm, Manuscript submitted. 10

15 Synthese neuartiger Vanadium(IV/V)-Katalysatoren für die enantioselektive Oxidation von prochiralen Sulfiden Lina Fischer,Carola Schulzke * Institut für Biochemie, Universität Greifswald Felix-Hausdorffstraße 4, Greifswald lina.fischer@uni-greifswald.de Presentation Die Bandbreite der bekannten stickstoffund/oder sauerstoffhaltigen Vanadiumkatalysatoren soll um die schwefelhaltigen Dithiolene erweitert werden. Die Dithioleneinheit ist aus den aktiven Zentren der Molybdän- und Wolframoxidoreduktasen bekannt. Dithiolene besitzen einen sogenannten non-innocent - Charakter, d.h. sie nehmen Einfluss auf die Oxidationszahl des Metallzentrums und können so Oxidations- bzw. Reduktionsreaktionen beeinflussen. Die Verbindung dieses Ligandentyps mit Vanadium könnte zu vielversprechenden Katalysatoren für Oxidationsreaktionen führen. Bis- und Tris-Dithiolen-Vanadium-Komplexe sind in der Literatur [1,2,3] beschrieben und gelten als thermodynamisch stabil und somit katalytisch inaktiv. Diese werden von Vanadium bevorzugt gebildet, da es stark zur Bildung homoleptischer Komplexe neigt. Um das Vanadiumzentrum in eine heteroleptische Konformation zu bringen und somit Mono- Dithiolen-Vanadium-Komplexe zu erhalten, wird an der Synthese von sterisch anspruchsvollen Liganden und Dithiolenen gearbeitet. Später soll das Ligandensystem um chirale Liganden erweitert werden. Mono-Dithiolen-Vanadium-Komplexe sollen dann schließlich in der enantioselektiven Oxidation von prochiralen Sulfiden zur Synthese von chiralen Sulfoxiden getestet werden, da chirale Sulfoxide wichtige Bausteine in der Synthese von chiralen Feinchemikalien und Pharmazeutika darstellen. [1] J. A. McCleverty, J. Locke, B. Ratcliff, E. J. Wharton Inorg. Chim. Acta 1968, 3, 283. [2] J. J. A. Cooney, M. D. Carducci, A. E. McElhaney, H. D. Selby, J. H. Enemark, Inorg. Chem. 2002, 41, [3] T. Suzuki, K. Ueda, R. Kita, S. Kokado, K. Harigaya Polyhedron 2005, 24,

16 Vom Alkinkomplex zum kohlenstoffbasierten FLP Helge Lange, Kai Helmdach, Alexander Villinger, Wolfram W. Seidel* Institut für Chemie, Universität Rostock Albert-Einstein-Straße 3a, Rostock Presentation Frustrierte Lewis Säure-Base-Paare (FLP), vor allem mit Boranen und Phosphanen, zeigen ein bemerkenswertes Reaktionsverhalten und somit großes Potential in der Aktivierung von Substraten und der Katalyse von Hydrierungen.[1] Obwohl Carbokationen isoelektronisch zu Boranen sind, wurden sie in diesem Zusammenhang bisher wenig untersucht. Reaktionen von Tritylkation mit Phosphanen führen in Abhängigkeit ihres sterischen Anspruches zu unterschiedlichen Addukten.[2] Mit Silyliumionen hingegen sind sowohl inter- als auch intramolekulare FLPs bekannt.[3,4] Inspiriert durch das intramolekulare FLP 1, haben wir in α-position funktionalisierte Wolfram- Alkin-Komplexe als Präkursor genutzt, um durch Dehydratisierung zur Verbindung 2 zu gelangen.[5] Dieses metallstabilisierte intramolekulare FLP mit einem Carbokation als Lewis- Säure konnte kinetisch stabilisiert und somit hinsichtlich seiner Reaktivität untersucht werden. [1] D. W. Stephan, G. Erker, Angew. Chem., Int. Ed. 2010, 49, [2] S. A. Weicker, D. W. Stephan, BCSJ 2015, 88, [3] A. Schäfer, M. Reißmann, A. Schäfer, W. Saak, D. Haase, T. Müller, Angew. Chem. 2011, 123, [4] M. Reissmann, A. Schäfer, R. Panisch, M. Schmidtmann, M. Bolte, T. Müller, Inorg. Chem. 2015, 54, [5] A. S. Balueva, G. N. Nikonov, Russ. Chem. Bull. 1993, 42,

17 Erleuchtete Wege zu Monodithiolenkomplexen des Wolframs und des Molybdäns Benedict Elvers, Christian Fischer* Institut für Biochemie, Felix-Hausdorff-Str. 4, Greifswald Presentation Die Kombination aus den Metallen Wolfram oder Molybdän mit Dithiolenliganden wird in der Natur ubiquitär für den Transfer von formal einem Sauerstoffatom [O] von oder auf ein Substrat genutzt. In unserem Projekt wollen wir diese offensichtlich erfolgreiche Strategie der Katalyse von Redoxreaktionen nutzen und Sie für unsere Zwecke adaptieren. Dazu sollen Monodithiolenkomplexe der entsprechenden Metalle synthetisiert werden. Während im Falle der Bisdithiolenkomplexe einige Syntheserouten in der Literatur beschrieben wurden, sind von Monodithiolenkomplexen nur wenige Beispiele bekannt. Dabei werden meist die als Ester der Kohlensäure oder (Thio)Phosphorsäure geschützten Dithiolene verseift, um diese dann in einer Ligandensubstitution an das Metall zu koordinieren. Die dazu benötigten Metallprekursoren sind aber oft sehr schwer zu handhaben, erzeugen viele Nebenreaktionen oder aber führen ausschließlich zu Bisdithiolenkomplexen. Wie nutzen in unserem völlig neuen Ansatz die bekannte non innocence Eigenschaft der Dithiolenliganden und entfernen die Schutzgruppe homolytisch unter Abspaltung von Kohlenmonooxid mittels Photolyse (Abb., links). Das dadurch entstandene, äußerst instabile Dithion kann nun mit geeigneten Carbonylkomplexen unter Oxidation des Zentralmetalls zum Dithiolenkomplex reagieren (Abb., rechts). Abbildung links: Photolyse von geschützten Dithiolenen; rechts: Photolytisch hergestellter Wolframmono-dithiolenkomplex [W(dppe)(cydt)(CO) 2] 2 (cydt = cyclohexan-1,2-dithiolen) [1] E. Stiefel, Dithiolene Chemistry, Vol. 52 in Progress in Inorganic Chemistry, 2004, John Wiley & Sons, Baltimore, Maryland. [2] B. Elvers, C. Schulzke, C. Fischer, in preparation. 13

18 In-depth Mechanistic Investigations of the Rhodium Catalyzed Propargylic CH Activation Saskia Moeller, Antje Meißner, Julia Rueger, Hans-Joachim Drexler and Detlef Heller* Leibniz-Institute for Catalysis (LIKAT), Albert-Einstein Straße 29a, Rostock Presentation Dinuclear neutral rhodium(i) complexes are widely known as efficient pre-catalysts in selective additions of carboxylic acids to terminal alkynes, [1] hydroacylations [2] or asymmetric ring opening reactions. [3] Rhodium(I) pre-catalysts of the type [Rh(diphosphine)(µ2-Cl)]2 are usually generated in situ. Depending on the diphosphine ligand, the rhodium precursor and other reaction conditions a variety of complexes beside the target one are formed. Herein, selectivity issues in the rhodium catalyzed coupling of terminal alkynes with carboxylic acids will be discussed (Figure 1). [1a] Additionally, we present a thorough investigation using various spectroscopic methods (NMR, Raman) and DFT calculations to clarify the reaction mechanism and the catalyst deactivation of the rhodium mediated CH activation. Fig. 1: Reaction scheme of the redox-neutral atom economic rhodium catalyzed coupling of terminal alkynes with carboxylic acids. [1] a) U. Gellrich, A. Meissner, A. Steffani, M. Kahny, H. J. Drexler, D. Heller, D. A. Plattner, B. Breit. J. Am. Chem. Soc., 2014, 136, b) S. Wei, J. Pedroni, A. Meissner, A. Lumbroso, H.-J. Drexler, D. Heller, B. Breit. Chem. Eur. J., 2013, 19, [2] a) A. Bouisseau, M. Gao, M. C. Willis. Chem. Eur. J., 2016, 22, b) K. F. Johnson, E. A. Schneider, B. P. Schumacher, A. Ellern, J. D. Scanlon, L. M. Stanley. Chem. Eur. J., 2016, 22, [3] a) M. Lautens, K. Fagnou, D. Yang. J. Am. Chem. Soc., 2003, 125, b) A. Preetz, C. Kohrt, H.-J. Drexler, A. Torrens, H. Buschmann, M. Garcia Lopez, D. Heller. Adv. Synth. Catal., 2010, 352,

19 Rhenium Complexes with Proton Responsive Ligands as Redox Catalysts in the CO2 Reduction Reaction Jia-Pei Du, Alexander Wilting, Jennifer Ahrens, Dirk Schwarzer, Inke Siewert* Institut für Anorganische Chemie, Georg-August Universität Göttingen Tammannstraße 4, Göttingen Presentation The electrochemical reduction of CO 2 has been investigated intensively since it represents a key step towards the use of CO 2 as a powerful and cheap fuel source or as chemical feedstock. [1] The multielectron reduced products of CO 2 are very similar in energy, thus, its reduction necessitates catalysts that are selective in the formation of one of the multiple products. Additionally, the catalyst must bypass the high-energy radical CO 2. One of the best explored catalyst families in this respect are the group 7 tricarbonyl-diimine complexes. [2] Recently, a detailed mechanism has been proposed for the reduction of CO 2 catalyzed by rhenium carbonyl complexes. [3] In the one-electron pathway, a dimer is the crucial species and, thus, a dinuclear complexe could speed-up catalysis. Furthermore, an internal proton source could be very beneficial, since efficient PCETs may be facilitated. This prompted us to synthesize a pair rhenium(i) carbonyl complexes using an already established ligand system [4] in order to address the questions, whether the dinuclearity and the internal proton source plays a crucial role during CO 2 reduction catalysis. [1] A. Tatin, M. Bonin, ACS Energy Lett. 2016, [2] J. Hawecker, J.-M. Lehn, J. Chem. Soc., Chem. Commun. 1983, 9, ; b) J. Hawecker, J.-M. Lehn, R. Ziessel, J. Chem. Soc., Chem. Commun. 1984, 984 (6), ; c) J. Hawecker, J.-M. Lehn, R. Ziessel, Helv. Chim. Acta 1986, 69, ; d) H. Takeda, O. Ishitani, Coord. Chem. Rev. 2010, 254 (3 4), ; e) K. A. Grice, C. P. Kubiak, Adv. Inorg. Chem. 2014, 66, f) C. Riplinger, M. D. Sampson, A. M. Ritzmann, C. P. Kubiak, E. A. Carter, J. Am. Chem. Soc. 2014, 136, [3] J. Agarwal, E. Fujita, H. F. Schaefer, J. T. Muckerman, J. Am. Chem. Soc. 2012, 134, [4] A. Wilting, T. Stolper, R. A. Mata, I. Siewert., Inorg. Chem. 2017, 56,

20 C H Bindungsaktivierung von Phosphoryliden an Bis(η 5 :η 1 - pentafulven)titankomplexen Generierung eines zick-zack Hexapentaene H2C=C=C=C=C=CH2 Komplexes Tim Oswald, Rüdiger Beckhaus* Institut für Chemie, Carl von Ossietzky Universität Oldenburg, D Oldenburg Presentation Pentafulvenkomplexe der frühen Übergangsmetalle haben sich aufgrund der Umpolung der C exo Position des Pentafulvenliganden sowie des Ausbleibens kinetischer Hemmungen im Vergleich zu klassischen Titanocenalkylen als vielseitige Synthesebausteine erwiesen. [1-4] Die Reaktion der Bis(η 5 :η 1 - pentafulven)titankomplexe Ti1a und Ti1b mit Phosphoryliden führt zu einer raschen C H-Aktivierung der Methyleneinheit unter milden Bedingungen. Unabhängig der gewählten Substituenten wird in allen Fällen nur eine einfache Bindungsaktivierung beobachtet. Durch Verwendung von Allylidentriphenylphosphoran hingegen wird eine doppelte C H-Aktivierung beobachtet, welche nach Abspaltung von Triphenylphosphan zur Generierung eines Titanabutatrien Intermediates [Cp 2Ti=C=C=CH 2] führt. Durch Dimerisierung dieses hochreaktiven Teilchens werden die zick-zack Hexapentaen Komplexe in guten Ausbeuten erhalten. Aufgrund der kumulierten Struktur des koordinierten Hexapentaens unterscheiden diese sich maßgeblich von bekannten zick-zack Diin Komplexen. Hierbei ist hervorzuheben, dass ein unsubstituiertes Hexapentaen H 2CCCCCCH 2 gewöhnlich in situ erzeugt und mit einem geeigneten Reagenz abgefangen werden muss. Solche Kumulenstrukturen sind im Hinblick auf ihre besonderen Eigenschaften als molekulare Drähte oder nichtlineare optische Materialen Gegenstand aktueller Forschungen. [5] [1] H. Ebert, V. Timmermann, T. Oswald, W. Saak, M. Schmidtmann, M. Friedemann, D. Haase, R. Beckhaus, Organometallics 2014, 33, [2] M. Diekmann, G. Bockstiegel, A. Lützen, M. Friedemann, D. Haase, W. Saak, R. Beckhaus, Organometallics 2006, 25, 339. [3] A. Scherer, S. Fürmeier, D. Haase, W. Saak, R. Beckhaus, A. Meetsma, M. W. Bouwkamp, Organometallics 2009, 28, [4] M. Manßen, N. Lauterbach, J. Dörfler, M. Schmidtmann, W. Saak, S. Doye, R. Beckhaus, Angew. Chem. 2015, 127, [5] J. A. Januszewski, R. R. Tykwinski, Chem. Soc. Rev. 2014, 43,

21 In situ spectroscopic studies of the Cu I /TEMPO mediated aerobic alcohol oxidation Sven Adomeit, Jabor Rabeah, Annette-E. Surkus, Ursula Bentrup, Angelika Brückner* Leibniz-Institut für Katalyse e.v. an der Universität Rostock Albert-Einstein-Straße 29A, Rostock Sven.Adomeit@catalysis.de Presentation Alcohol oxidations belong to the most important functional group transformations within chemical industry. Over the last three decades several methods utilizing nitroxyl radicals in combination with transition metal ions and O2 or ambient air as the terminal oxidant have been explored as a green alternative. [1] Especially the Cu I /2,2-bipyridine/NMI/TEMPO system developed by Stahl et al. demonstrated the efficacy of an in-situ formed homogeneous Cu complex in the conversion of both aromatic and aliphatic alcohols. [2] However, several open questions remain, in particular the specific role of the ligand in the catalytic system and the nature of the active Cu species. To elucidate the influence of the ligands on catalyst performance and active complex formation, NMI as well as other substituted imidazoles have been tested in the oxidation of benzyl alcohol to benzaldehyde as a model reaction. In situ EPR, UV-vis and ATR-IR spectroscopy were simultaneously applied to study changes of Cu oxidation state and complex formation (EPR/UV-vis) as well as benzaldehyde formation (ATR-IR) in dependence on the used ligands (Fig. 1). These studies were further corroborated by X-ray absorption spectroscopy (XAS) and electrochemical measurements. A B Figure 1. A) Formation of benzaldehyde as a function of time for various N-substituted imidazoles B) Corresponding EPR signal amplitude and CT bands for 1- ethylimidazole [1] Cao, Q.; Dornan, L. M.; Muldoon, M. J., Chem. Commun., 2014, 50, 4524 [2] Hoover, J. M.; Stahl, S. S., J. Am. Chem. Soc. 2011, 133,

22 Concepts for the Synthesis of a Tetrazabismuthole Max Thomas, Axel Schulz*and Alexander Villinger Institut für Chemie, Universität Rostock Albert-Einstein-Straße 3a, 18095, Rostock max.thomas@uni-rostock.de Presentation Formal aromatic ring systems consisting solely of pnictogens (Group 15 elements) are known since the investigations on pentazoles by Huisgen and Ugi. [1] Within the last 12 years, it was possible to synthesize analogous ring systems where the nitrogen atom is replaced by a heavier pnictogen atom (P, As, Sb). [2-4] However, the corresponding bismuth compound, the tetrazabismuthole RN4Bi, remains elusive so far. In this presentation, we will portray different concepts for the synthesis of tetrazabismuthole, such as the elimination of Me3E groups (E = Si, Sn) from suitable NBi precursors, the attempted generation of cyclo-dibismadiazanes and reactions of tetrazenides with Bi1 building blocks (Scheme 1). R N EMe 3 BiCl 2 1) Me 3 SiN 3 2) LA - Me 3 ECl - Me 3 SiCl R N Bi N N N LA LA 1 / 2 R N N 3 Bi N Bi N 3 R LA - R'Cl Cl R Bi N N R' N N Scheme 1: Investigated synthetic strategies for tetrazabismutholes (E = Si, Sn; LA = Lewis acid). [1] R. Huisgen, I. Ugi, Chem. Ber. 1957, 90, [2] A. Villinger, P. Mayer, A. Schulz, Chem. Commun. 2006, [3] A. Schulz, A. Villinger, Angew. Chem., Int. Ed. 2008, 47, [4] M. Lehmann, A. Schulz, A. Villinger, Angew. Chem., Int. Ed. 2011, 50,

23 Tetrylenes Stabilized by Homoconjugation Zhaowen Dong, Crispin R. W. Reinhold, Thomas Müller * Carl von Ossietzky University of Oldenburg, Institute of Chemistry, Carl von Ossietzky Straße 9-11, D Oldenburg, European Union zhaowen.dong@uni-oldenburg.de Presentation Carbene analogues such as tetrylenes have small HOMO-LUMO gaps and exhibit properties reminiscent to transition metal complexes. Therefore, they can be applied in small molecule activation (H2, CO2, NH3) and bond activation reactions. [1] Against this background, the exploration of new types of tetrylenes has been a hot topic in main group chemistry during recent years. The synthesis of stable tetrylenes is however challenging due to their high inherent reactivity. Here we report on the synthesis of stable bicyclohexene silylene (BCHSi) 2a and germylene (BCHGe) 2b by the reaction of dipotassium heterocyclopentadienediides 1 and hafnocene dichloride. [2] The tetrylenes 2a and 2b are stabilized by interaction with the remote C 2 =C 3 double bond through homoconjugation. The preliminary reactivity studies of tetrylenes 2 revealed their predominant nucleophilic character. Scheme 1. Synthesis of bicyclohexene tetrylenes (BCHTs) 2. [1] a) V. Y. Lee & A. Sekiguchi, Organometallic Compounds of Low- Coordinate Si, Ge, Sn, and Pb (Wiley, 2010). b) P. P. Power, Nature 2010, 463, c) M. Driess, Nature Chemistry 2012, 4, d) M. Usher, A. V. Protchenko, A. Rit, J. Campos, E. L. Kolychev, R. Tirfoin, S. Aldridge, Chem. Eur. J. 2016, 22, [2] a) Z. Dong, C. R. W. Reinhold, T. Müller, Angew. Chem. Int. Ed. 2016, 55, b) Z. Dong, C. R. W. Reinhold, M. Schmidtmann, T. Müller, J. Am. Chem. Soc. 2017, 139,

24 Trends in Synthesis and Reactivity of Stannoles Sara Urrego-Riveros, Isabel M. Ramírez y Medina, Anne Staubitz* Institute for Organic and Analytical Chemistry, University of Bremen Leobener Str.7, 28359, Bremen Surregor@uni-bremen.de Presentation Stannoles are cyclopentadiene analogues where the saturated carbon is replaced by a tin atom. Due to the low lying σ* orbitals of the tin-substituted bond in stannoles, they are capable of π*σ*-conjugation in a way that is exclusive to heavier element containing heterocycles. 1,2 Thus stannoles are attractive alternatives for purely organic heterocycles. They are of high interest in material applications where optoelectronic properties are important. 3 Here we report on the synthesis of stannoles, where two of them contain functional nucleophilic groups (-BPin and -SnMe3) which can be tested in further cross coupling reactions. The synthetic pathway to obtain them starts from a zirconacyclopentadiene derivative, which is prepared from an alkyne and a low valent zirconocene species. Here a detailed comparison of two zirconocene species namely the Rosenthal reagent, 4 and Negishi reagent is presented. 5 The stannole s synthetic route is completed by a Zr-Cu-Sn transmetallation. 6 [1] Hissler, M.; Dyer, P. W.; Réau, R., Coord. Chem. Rev 2003, 1, 1. [2] Yamaguchi, S.; Itami, Y.; Tamao, K., Organometallics 1998, 17, [3] Yamaguchi, S.; Tamao, K., J. Chem. Soc., Dalton Trans. 1998, 22, [4] Rosenthal, U.; Ohff, A.; Baumann, W.; Tillack, A.; Görls, H.; Burlakov, V. V.; Shur, V. B., Struktur, Anorg. Allg. Chem. 1995, 621, 77. [5] Negishi, E.; Holmes, S. J.; Tour, J. M.; Miller, J. A.; Cederbaum, F. E.; Swanson, D. R.; Takahashi, T., J. Am. Chem. Soc. 1989, 111, [6] Ura, Y.; Yanzhong, L.; Zhenfeng, X.; Takahashi, T.,Tetrahedron Lett. 1998, 39,

25 An iron PNP pincer complex for dehydropolymerisation of methylamine borane Felix Anke, Monica Ferro, Anke Spannenberg, Torsten Beweries* Leibniz-Institut für Katalyse e.v. Albert-Einstein-Str. 29a, Rostock Presentation Catalytic routes for the formation of bonds between main group elements are very important for targeted construction of new molecules and materials. In contrast to the formation of C-C bonds or C-X bonds, main group bond-forming reactions lag behind. For instance catalytic dehydropolymerisation reactions of amine borane adducts (RNH2 BH3, R = H, Me) provide a clean, atom efficient route to synthesise polyamineboranes, involving the loss of hydrogen. These polymeric BN materials are isoelectronic to technologically versatile polyolefins and are discussed as high performance polymers, as precursor to BN-based ceramics and single-layer hexagonal BN thin films (white graphene). [1] In 2010 the Manners group demonstrated that MeNH2 BH3 can be dehydrocoupled by transition metal complexes to afford a linear polyamineborane. [2] In recent years our group focused on the catalytic dehydrogenation of dimethylamine borane to dimeric compounds by group 4 metallocene complexes. [3] Herein we describe the use of iron pincer complexes as highly active catalysts for dehydrocoupling of methylamine borane at room temperature to give mainly linear high molecular weight polyamineborane. [4] [1] H. C. Johnson, E. M. Leitao, G. R. Whittell, I. Manners, G. C. Lloyd-Jones, A. S. Weller, J. Am. Chem. Soc. 2014, 136, [2] A. Staubitz, M. E. Sloan, A. P. Robertson, A. Friedrich, S. Schneider, P. J. Gates, J. S. a. d. Guenne, I. Manners, J. Am. Chem. Soc. 2010, 132, [3] a) T. Beweries, S. Hansen, M. Kessler, M. Klahn, Uwe Rosenthal, Dalton Trans. 2011, 40, ; b) M. Klahn, D. Hollmann, A. Spannenberg, A. Brückner, T. Beweries, Dalton Trans. 2015, 44, [4] F. Anke, D. Han, M. Klahn, A. Spannenberg, T. Beweries, Dalton Trans. 2017,46,

26 Tuning of Tc through mixed crystal formation in thiocyanate coordination polymers with ethylisonicotinate Tristan Neumann, Carsten Wellm and Christian Näther * Institut für Anorganische Chemie der Christan Albrechts Universität zu Kiel Max-Eyth-Straße 2, Kiel t.neumann@online.de Presentation The synthesis of new coordination compounds with desired magnetic properties is still a growing field in coordination chemistry. Most of them consist of only one kind of metal cation and their diversity can be traced back to the fact that different ligands are used. In other cases bimetallic compounds are synthesized, which can be achieved by using multifunctional ligands that can coordinate to different metal cations or by the use of predefined metal containing building blocks and additional metal cations. In comparison, only very few papers report on the synthesis of mixed crystals as an additional tool to further modify or tune the magnetic properties of coordination compounds in more detail. In our own investigations, we are especially interested in the magnetic properties of thio- or selenocyanate coordination polymers based on transition metal thio and selenocyanates with pyridine derivatives as co-ligands, in which the metal cations are linked by the anionic ligands into 1D or 2D coordination networks. In the course of our investigations we obtained two 2D compounds with the composition [M(NCS)2(4-ethylisonicotinate)2]n with (M = Co or Ni). The Co compound shows ferromagnetic ordering at 1.72 K whereas the ferromagnetic transition of the Ni compound is shifted to 8.7 K. [1] In this context the question arose whether it would be possible to prepare mixed crystals with the composition [CoxNi1-x(NCS)2(ein)2]n and how this would influence the magnetic properties. To prove mixed crystal formation, the results of most of the measurements were compared with those obtained for physical mixtures with the same metal to metal ratio. Magnetic measurements prove that depending on the actual composition, a continuous change of the magnetic properties is observed but there are indications that samples obtained from solution are not homogenous. Therefore, precursor compounds with the composition CoxNi1-x(NCS)2(ein)4 were prepared, which upon thermal decomposition transform into mixed crystals of the desired compounds. In this case much more homogenous samples are obtained. [1] S. Suckert, M. Rams, M. Böhme, L. S. Germann, R. E. Dinnebier, W. Plass, J. Werner and C. Näther, Dalton Trans 2016, 45,

27 A supramolecular approach: artificial metalloproteases based on the oxacyclen ligand Sebastián Hinojosa, Nils Hatje, Nora Kulak* Institute of Chemistry and Biochemistry, Freie Universität Berlin Fabeckstrasse 34-36, 14195, Berlin Presentation Metal complexes based on the macrocyclic ligand 1,4,7,10-tetraazacyclododecane (cyclen) have proven to be suitable compounds for the cleavage of proteins. Rational modifications of this scaffold lead to an increase of the cleavage activity. Within this field, two options have caught our attention. One is the exchange of the heteroatoms for enhancing the cleavage activity, by changing the coordination sphere. The other is the attachment of long alkyl chains with the aim of increasing the local complex density through micelle formation. Recently we have expanded our approach of designing amphiphilic Cu(II) complexes to the synthesis of amphiphiles derived from 1-oxa-4,7,10-triazacyclododecane (oxacyclen). Our results have shown that by introducing alkyl chains of different length, the proteolytic activity towards model proteins such as bovine serum albumin (BSA) and myoglobin (Myo) can be selectively modulated. Thus, derivatives with a C-18 chain can cleave ten times more efficiently than derivatives with a C-12 chain under near physiological conditions. Now that characterization and trend recognition has been performed, we expect to expand our scope to the synthesis of higher order structures like dendritic amphiphiles, time dependent cleavage studies and targeting of specific substrates found in proteopathies such as Alzheimer s disease. [1] Perera-Bobusch et al., Dalton Trans. 2016, 45, [2] J. Suh, Asian J. Org. Chem, 2014, 3, [3] B. Gruber et al., J. Am. Chem. Soc. 2011, 133,

28 Sila-Ibuprofen Florian Kleemiss, Daniel Duvinage, Patrick Watermann, Aileen Justies, Werner Reutter, Nelly Rivas King, Eric Ehrke, Jens Beckmann, Ralf Dringen, Simon Grabowsky* Insitute of Inorganic Chemistry and Crystallography, University of Bremen Leobener Straße NW2, Bremen Presentation Ibuprofen is one of the TOP 10 most imprtant drugs by the WHO. Here we present the silasubstituted analogon which promises to be an even more potent drug. Carbon-Sila-substitution is an already documented concept for pharmaceutical compounds.[1][2] A synthesis method for sila-ibuprofen was tested and established. The resulting substance shows a lower melting point and higher solubility in almost every media and therefore has possible application in local treatment after operations or as anesthetic. First tests on biological systems show promising features for the application. The effect of enantiomers of ibuprofen on the biological systems was investigated through separation of the Enantiomers as reported in the literature.[3] To get insight into the similarities and differences between the two substances, an analysis of the bonding patern, electrostatic potential and situation in the crystals was performed using high resolution synchrotron diffraction experiments and quantum-crystallographic analyses. [1] M. Geyer, E. Wellner, U. Jurva, S. Saloman, D. Armstrong, R. Tacke, ChemMedChem 2015, 10, [2] A. K. Franz, S. O. Wilson, Journal of medicinal Chemistry 2013, 56, [3] J. V. McCullagh, Journal of Chemical Education 2008, 85,

29 Seltenerdmetallkomplexe mit einem sterisch anspruchsvollen Pentadienyl-Liganden Eigenschaften und Reaktivität J. Raeder, M. Reiners, M. Freytag, P. G. Jones, M. D. Walter Technische Universität Braunschweig, Institut für Allgemeine und Anorganische Chemie Hagenring 30, Braunschweig Presentation Seit ihrer Erwähnung/Einführung in die/der Literatur durch Ernst und Taube in den 1980er Jahren sind Pentadienyl-Liganden inzwischen weit in der Koordinationschemie verbreitet [1]. Sie sind aufgrund ihrer vielseitigen Bindungsmoden und ihrer Kombination von Eigenschaften der Allyl- und Cyclopentadienyl-Liganden von besonderem Interesse [2a-c]. Neben ihren guten π-donor- und δ-akzeptor-eigenschaften, sind sie vor allem sterisch deutlich anspruchsvoller als vergleichbare Cp-Liganden und bilden daher interessante Koordinationsverbindungen. Basierend auf vorangegangenen Arbeiten auf dem Gebiet mit schweren Erdalkalimetallen und Übergangsmetallen sowie den Arbeiten von Ernst und Taube beschäftigen wir uns mit der Koordinationschemie der seltenen Erden mit unserem 2,4-Di-tert-butylpentadienyl-Liganden (Pdl ) [3-6]. Neben der Synthese und Charakterisierung der verschiedenen Metallkomplexe wird auch deren Reaktivität gegenüber kleinen Molekülen präsentiert. [1] Ernst, R.D., Acc. Chem. Res.1985, 18, 56. [2] a) Ernst, R.D., Chem. Rev. 1988, 88, b) Ernst, R.D., Comments Inorg. Chem. 1999, 21, 285. c) Stahl, L, Ernst, R.D., 2007, 55, 137. [3] Reiners, M., Fecker, A.C., Freytag, M, Jones, P.G. and Walter, M.D., Dalton Trans 2014, 43, [4] Reiners, M., Baabe, D, Freytag, M., Jones, P.G. and Walter, M.D., Organometallics 2016, 35, [5] Ernst, R.D. and Cymbaluk, T.H., Organometallics 1982, 1, 708. [6] Kunze, M.R., Steinborn, D., Merzweiler, K, Wagner, C., Sieler, J. and Taube, R., Z. Anorg. Allg, Chem. 2007, 633,

30 Growth and characterization of single crystalline alpha- and beta- PbAlBO4 M. Gogolin a, M. M. Murshed a,b, Th. M. Gesing a,b, * a Universität Bremen, Institut für Anorganische Chemie und Kristallographie, Leobener Straße 7, Bremen; b Universität Bremen, MAPEX Center for Materials and Processes, Bibliothekstrasse 1, Bremen mathias.gogolin@uni-bremen.de Presentation Single-crystals of α- and β-pbalbo4 [1, 2] were grown from identical melts consisting of Al2O3 along with an excess of PbO and B2O3, using different cooling regimes for the two phases. The two polymorphs differ in the shape of the AlO6 octahedral chains as main structural motive with identical chain-connecting building units. α-pbalbo4 (Pnam) belongs to the mullite-type compounds characterized by edge-sharing linear chains parallel to the c-axis (Figure) whereas β-pbalbo4 (Pbcn) shows pyromorphite-type 3x3 zig-zag chains. A comparative structural and spectroscopic study was performed using temperature-dependent X-ray diffraction and Raman spectroscopy, which shed light to understand the in-depth thermal behaviors of these phases. The bandgaps were calculated from UV-Vis reflectance data treated by both the Tauc [3] and DASF [4] method. Several transitions could be observed in both materials, with the α-phase possessing a direct bandgap at 3.23(2) ev and the β-phase an indirect one at 2.19(3) ev. Figure: Mullite-type α-pbalbo 4 (left) and β-pbalbo 4 featuring zigzag- chains (right) [1] H. Park, J. Barbier, Acta Crystallogr. E 2001, i82. [2] H. Park, J. Barbier, R. P. Hammond Solid State Sci , 565. [3] J. Tauc, R. Grigorovici, A Vancu, Phys. Stat. Sol , 627. [4] D. Souri, Z. E. Tahan, Appl. Phys. B ,

31 Organoantimony(III)-containing Polyoxometalates: Tuning of Bioactivity by Ligand Functionalization Tian Ma and Ulrich Kortz* Department of Life Sciences and Chemistry, Jacobs University Campus Ring 1, Bremen Presentation Polyoxometalates (POMs) are discrete polynuclear metal oxides with a large structural and compositional variety, and a multitude of properties resulting in applications in fundamental and applied science. 1 In recent years our group has pioneered the class of organoantimony(iii)-containing POMs and we have demonstrated bioactivity with a focus on bacterial inhibition. Most importantly, it was shown that the number and type of grafted organoantimony(iii) groups have a strong influence on the resulting bioactivity of the polyanion. 2 Here we show recent developments in this area of research. [1] (a) M. T. Pope, Heteropoly and Isopoly Oxometalates, Springer, Berlin, (b) M. T. Pope, A. Müller, Polyoxometalates: from Platonic Solids to Antiviral Activity; Kluwer Academic Publishers: Dordrecht, The Netherlands, [2] (a) P. Yang, Z. Lin, B. S. Bassil, G. Alfaro-Espinoza, M. S. Ullrich, M. X. Li, C. Silvestru, U. Kortz, Inorg. Chem. 2016, 55, (b) P. Yang, Z. Lin, G. Alfaro-Espinoza, M. S. Ullrich, C. I. Rat, C. Silvestru, U. Kortz, Inorg. Chem. 2016, 55, (c) P. Yang, B. S. Bassil, Z. Lin, A. Haider, G. Alfaro-Espinoza, M. S. Ullrich, C. Silvestru, U. Kortz, Chem. Eur. J. 2015, 21, (d) M. Barsukova-Stuckart, L. F. Piedra-Garza, B. Gautam, G. Alfaro-Espinoza, N. V. Izarova, A. Banerjee, B. S. Bassil, M. S. Ullrich, H. J. Breunig, C. Silvestru, U. Kortz, Inorg. Chem. 2012, 51, (e) L. F. Piedra-Garza, M. H. Dickman, O. Moldovan, H. J. Breunig, U. Kortz, Inorg. Chem. 2009, 48,

32 Syntheseoptimierung von Zr-Cluster-Verbindungen Jonas Jablonski und Martin Köckerling* Institut für Chemie, Universität Rostock Albert-Einstein-Str. 3a, Rostock Presentation Metallcluster-Verbindungen, also polynukleare Koordinationsverbindungen, in denen Metall- Metall-Bindungen vorliegen, [1] sind von den meisten Metallen des Periodensystems bekannt. Umgeben von Liganden (Halogenide, Chalkogenide und auch organische Moleküle) bilden sich je nach Metall-Ligand-Verhältnis charakteristische Metallatom-Polyeder. Elemente dervierten Gruppe bilden oft einen Oktaeder aus Metallatomen, welcher von zwölf, über den Kanten liegenden, sogenannten inneren Liganden umgeben ist. Über den Ecken des Oktaeders liegen zusätzlich sechs sogenannte äußere Liganden. Zur elektronischen Stabilisierung befindet sich mindestens ein Interstitialatom (z.b. H, B, C, Fe oder Co) im Zentrum des Oktaeders. [2][3] Viele dieser Verbindungen sind in organischen Lösungsmitteln löslich, was den Austausch vor allem der äußeren Liganden durch organische Moleküle ermöglicht. Zr-Cluster werden bisher bei Temperaturen über 700 C mit einer Reaktionszeit von mehreren Wochen synthetisiert. Als Reaktionsgefäße dienen in der Regel in evakuierte Quarzampullen eingeschlossene, Nb- oder Ta- Ampullen. In dieser Arbeit haben wir einen Ansatz entwickelt, mit dem wir die sehr aufwändige Synthese von Zr-Clustern auf festkörperchemischem Wege wesentlich vereinfachen können. Mit Hilfe einer Kombination aus thermoanalytischen- und XRD Methoden [4] lässt sich bei der Reaktion von Zr mit PbC l2 bereits bei 475 C (siehe Abb.1) die Bildung von Clustern nachweisen. Durch Tempern bei 475 C für zwei Tage erhält man ein amorphes Produkt, aus dem sich durch Extraktion mit Acetonitril die Verbindung [(Zr 6C)Cl 14(MeCN) 4] isolieren lässt. Bei diesen Reaktionsbedingungen kann auch Quarz als Ampullenmaterial verwendet werden, was das Procedere sehr vereinfacht. Abbildung 1: DSC der Reaktion von Zr mit PbC l2 in Gegenwart von C 6Cl 6 und KCl. Bei 216 C schmilzt C 6Cl 6 und bei 385 C entsteht ZrCl 3. [1] Cotton, F. A., Inorg. Chem. 1964, 3, [2] Simon, A., Angew. Chem. 1988, 100, [3] Corbett, J. D., Pure & Appl. Chem. 1992, 64, [4] Ströbele, M., Mos, A., Meyer, H.-J., Inorg. Chem. 2013, 52,

33 SynRAC A multi-purpose reaction cell for the investigation of reactions under solvothermal conditions N. Heidenreich a,b, U. Rütt b, M. Köppen a, A. K. Inge a, A. C. Dippel b, R. Suren a and N. Stock a, a Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Str. 2, Kiel b Deutsches-Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg Presentation Crystalline porous materials represent a class of compounds that are, due to their narrow pore size distribution and high specific surface area, well suited candidates for a wide area of applications including gas storage/ -separation, [1] heat transfer [2] and catalysis. [3] However resulting from harsh synthesis conditions the underlying principles of their formation as well as their interaction with guest molecules is not yet fully understood. Within the scope of the Röntgen-Ångström-Cluster the project MATsynCELL, a Swedish-German collaboration involving four universities as well as DESY and MAX IV aims at the construction of reaction cells that can easily be used at different synchrotron facilities to study chemical reactions in liquid medium in-situ. The reaction cell presented here was developed at CAU Kiel in collaboration with the staff of beamline P08, PETRA III, DESY to analyze reactions under solvothermal reaction conditions. The main focus of the design lay in a versatile reaction cell that is easy to handle and closely mimics the conditions present in a standard laboratory based synthesis. In addition to two sizes of reaction vessels based on commercially available borosilicate glass vials the reactor features a liquid injection system and a solid dosing device to for instance initiate very fast reactions, quench reactions or alter chemical parameters during the experiment in any other way. Figure 1: Centerpiece of SynRAC (schematic left, representational on the right). [1] A. U. Czaja, N. Trukhan and U. Müler, Chem. Soc. Rev., 2009, 38, [2] S. K. Henninger, F. Jeremias, H. Kummer, C. Janiak, Eur. J. Inorg. Chem., 2012, [3] A. Corma, H. Garcia and F. X. Llabrés I Xamena, Chem. Rev., 2010, 110,

34 POSTER 30

35 Ammonia synthesis mediated by PCET to an Ir nitride Josh Abbenseth, Markus Kinauer and Sven Schneider* Institut für Anorganische Chemie, Georg-August-Universität Göttingen Tammannstraße 4, 37077, Göttingen Poster The synthesis of ammonia has been of great interest in the recent decades due to the high economic costs of the Haber-Bosch process. [1] However studies on the full reduction of metal nitrides to ammonia remain scarce. Especially the bond strengths of the formed metal NHx (x = 1-3) species are ill defined. [2] The reaction of the d 4 nitride [IrN(PNP)] + (1) (PNP = N[CHCHPtBu2]2) with 1,4-cyclohexadiene produces the Ir III complex [IrH(PNP)(NH3)] + (2) via stepwise 4H + /4e - PCET (proton coupled electron transfer) [3] processes. The stepwise reaction can be followed by NMR spectroscopy. DFT computations and experimental N-H bond strength determination experiments elaborate the proposed mechanism and give insights into the overall thermochemistry of this unprecedented process for group 9 metal nitrides. 1 Scheme 1. Conversion of cationic nitride 1 with 1,4-cyclohexadiene to yield the ammine complex 2. [1] H. P, P. Leitgeb, B. Schmücker, Ullmann s Encyclopedia of Industrial Chemisty, Wiley-VCH, Weinheim, [2] a) M. G. Scheibel, J. Abbenseth, M. Kinauer, F. W. Heinemann, C. Würtele, B. de Bruin, S. Schneider, Inorg. Chem. 2015, 54, b) J. Rittle, J. C. Peters, J. Am. Chem. Soc. 2017, 139, c) M. J. Bezdek, I. Pappas, P. J. Chirik, Top. Organomet. Chem. 2017, 60, [3] a) J. J. Warren, T. A. Tronic, J. M. Mayer, S. V. G. Bond, Chem. Rev. 2010, 112, b) D. R. Weinberg, C. J. Gagliardi, J. F. Hull, C. F. Murphy, C. A. Kent, B. C. Westlake, A. Paul, D. H. Ess, D. Granville, T. J. Meyer, Chem. Rev. 2012, 112,

36 Synthesis of an o-quinone complex of Cu(I)(dppf) and its electrochemical investigations Uta Albold, Biprajit Sakrar* Freie Universität Berlin, Institut für Chemie und Biochemie, Anorganische Chemie Fabeckstrasse 34-36, Berlin Poster Interactions between copper centers and quinones are important for diverse research areas such as, among others, molecular devices or biochemical systems. These interactions are typically determined by certain redox couples of the copper and the quinone moiety, which is often in the semiquinone or catecholate redox form. Reports on isolated o-quinone copper(i) species are rather scarce, potentially due to the low stability of the copper(i) oxygen bond. [1][2] In this contribution the synthesis of a copper(i) complex with an o- quinone ligand and an organometallic co-ligand dppf (1,1ʹ-bis(diphenylphosphino)ferrocene is shown. X-ray crystallographic analysis of the complex were used to determine the redox state of the pyrene based ligand. Cyclic voltammetric and UV-Vis/NIR spectroelectrochemical measurements were conducted and show an oxidation process and several reduction processes, which were further investigated via EPR spectroelectrochemical measurements. The spectrum shows interesting hyperfine coupling possibly with the 31 P, 63,65 Cu and the ring protons of the ligand.[3] 2 [1] S. Roy, B. Sarkar, D. Bubrin, M. Niemeyer, S. Záliš, G. K. Lahiri, W. Kaim, J. Am. Chem. Soc. 2008, 130, [2] D. N. Hendrickson, C. G. Pierpont, Top. Curr. Chem. 2004, 234, 63. [3] C. G. Pierpont, Coord. Chem. Rev. 2001, ,

37 Stabilization of classical anhydrous Brønsted acids Kevin Bläsing, a Jonas Bresien, a René Labbow, a Alexander Villinger, a Axel Schulz* a,b a Institut für Chemie, Abt. Anorganische Chemie, Universität Rostock 3 Albert-Einstein-Straße 3a, 18059, Rostock b Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Abt. Materialdesign Albert-Einstein-Straße 29a, 18059, Rostock axel.schulz@uni-rostock.de Poster Pseudohalogen Brønsted Acids: [1] Until now, there are only a few investigations addressing the stabilization of classical, unstable pseudohalogen Brønsted acids (HX) and their trimethylsilyl analogs (Me3SiX) in anhydrous systems. [2] For example, the stabilization with bulky Lewis acids by adduct formation can give access to such labile systems. Recent results of our group revealed that it was possible to isolate and characterize a series of bissilylated halonium and pseudohalonium ions ([Me3Si X SiMe3] + ). [3] Furthermore, the stabilization and isolation of the highly reactive thionylimide (HNSO) was possible by adduct formation. [4] These previous results prompted us to investigate classical pseudohalogens like CN, N3, NCO and NCS. We could successfully stabilize the respective Brønsted acids by different Lewis acids. Using B(C6F5)3 and GaCl3, neutral donor-acceptor complexes could be formed and compared to the starting materials with respect to structure, stability and bonding situation. Interestingly, the adduct between HN3 and B(C6F5)3 was unstable and decomposed under N2 elimination to the aminoborane HN(C6F5)B(C6F5)2 (1, Scheme). R CN LA R NNN LA R NC LA R NNN LA R-CN Lewis Acid R-NCS R-N 3 R-NCO R NCO R NCS LA LA R NCO LA R NCS LA -N 2 (1) R = H, Me 3 Si LA = B(C 6 F 5 ) 3, GaCl 3 [1] L. Birkenbach, K. Kellermann, Ber. Dtsch. Chem. Ges. B 1925, 58, 786. [2] E. I. Davydova, T. N. Sevastianova, A. V. Suvorov, A. Y. Timoshkin, Coord. Chem. Rev. 2010, 254, [3] (a) M. Lehmann, A.Schulz, A. Villinger, Angew. Chem. Int. Ed. 2009, 48, 7444; (b) A. Schulz, A. Villinger, Chem. Eur. J. 2010, 16, [4] R. Labbow, D. Michalik, F. Reiß, A. Schulz, A. Villinger, Angew. Chem. Int. Ed. 2016, 55,

38 Synthesis and Characterisation of Terminal Group 9 Imido Complexes Daniel Delony, Markus Kinauer, Christian Würtele, Markus Finger, Bas de Bruin, Sven Schneider* Institut für Anorganische Chemie, Georg-August Universität Göttingen Tammannstr. 4, Göttingen daniel.delony@chemie.uni-goettingen.de Poster Nitren complexes are proposed intermediates for the direct catalytic amination of C-H bonds.[1] Especially group 9 metals are suitable for such reactivity due to the occupation of M-N σ- and/or π-antibonding molecular orbitals, which enhances the reactivity of the Nitren unit. But the consequential transient character complicates the characterisation. This contribution will show the synthesis and isolation of rhodium and iridium Imid complexes. Imid (3Rh) is only the second known terminal Imid complex of rhodium and the first one having a square planar conformation.[2] The electronic structure of the complexes will be discussed. 4 [1] C. G. Espino, P. M. Wehn, J. Chow, J. Du Bois, J. Am. Chem. Soc. 2001, 123, b) C. G. Espino, K. W. Fiori, M. Kim, J. Du Bois, J. Am. Chem. Soc. 2004, 126, [2] A. M. Geer, C. Tejel, J. A. Lòpez, M. A. Ciriano, Angew. Chem. 2014, 126,

39 Prodigiosin derivatives as potential ligands for metallonucleases Sebastian Doniz Kettenmann, Nora Kulak* Institute of Chemistry and Biochemistry, Freie Universität Berlin Fabeckstr , Berlin Poster Derivatives of prodigiosin, a natural product distinguished by a conjugated pyrrolyldipyrromethen structure, have widely been under investigation for various biological effects, including their antibacterial, immunosuppressive and cytotoxic properties.[1] Of particular interest is the promising DNA-cleaving activity that certain prodigiosin derivatives show in the presence of Cu(II).[2][3] With this aspect in mind, prodigiosins carry a great potential as ligands for metal-containing artificial nucleases, which represent a research subject of rising importance due to their possible application in the field of DNA-targeting chemotherapeutics. We have studied the implementation and optimization of an effective pathway for the synthesis of prodigiosin derivatives, with the ulterior motive of varying the heterocycle constitution and the substitution patterns. Particular emphasis has been put in the introduction of long alkyl chains as substituents, which at a later point in the research could favor particle aggregation in solution and the formation of metallomicelles with enhanced DNA-cleaving activity. 5 [1] P. A. Gale, M. E. Light, B. McNally, K. Navakhun, K. E. Sliwinski, B. D. Smith, Chem. Commun. 2005, 30, [2] M. S. Melvin, M. W. Calcutt, R. E. Noftle, R. A. Manderville, Chem. Res. Toxicol. 2002, 15, [3] A. Fürstner, E. J. Grabowski, ChemBioChem. 2001, 2,

40 The synthesis of 5-diphenylphosphinoacenaphth-6-yllithium Daniel Duvinage, Jens Beckmann* Institut für anorganische Chemie und Kristallographie, Universität Bremen Leobener Straße 7, 28359, Bremen Poster Organolithium derivatives are essential compounds in transmetalation and salt metathesis reactions. For substitution of the 5-diphenylphosphinoacenaphth-6-yl-group the organolithium is usually prepared in situ in diethyl ether with TMEDA as additive. [1] 5- diphenylphosphinoacenaphth-6-yllithium as toluene and diethylether solvate was first synthesized and isolated in this work. The two compounds were analyzed by multinuclear NMR-spectroscopy ( 1 H, 7 Li, 31 P) and determined by single-crystal-x-ray-diffraction. The organolithium was used to synthesize the phosphorus-containing compounds RPCl2, RPF2, R2PCl, R2PH, R2P(O)H and R3P. Further studies to the influence of donor additives to the organolithium are ongoing as well as the formation of mild transmetalation reagents as magnesium and zinc organyls from the organolithium 6 [1] J. Beckmann, T. G. Do, S. Grabowsky, Z. Anorg. Allg. Chem. 2013, 639,

41 Development of Ni and Co catalysts for the (co-)polymerization of olefins and polar monomers and hydrofunctionalization of olefins Andreea Enachi, Matthias Freytag, Peter G. Jones, Marc D.Walter* Institute for Inorganic and Analytical Chemistry, TU Braunschweig Hagenring 30, Braunschweig Poster. Transition metal alkyl complexes are among the most reactive species in organometallic chemistry, therefore preparing and isolating them can be a challenge. [1] However, we were able to synthesize dialkyl metal complexes in a good yield using [(tmeda)m(acac)2] (M=Ni, Co) as a M 2+ source and MgR2 (R= CH2SiMe3, CH2CMe2Ph, CH2CMe3) as the alkyl transfer reagent. Furthermore, the tmeda ligand can be readily displaced by tunable bidentate phosphines and N- heterocyclic carbenes (NHCs) which are good sigma donors and spectator ligands and confer good stability to transition metal complexes. 7 Scheme 1. Preparation of N-heterocyclic carbene Ni 2+ and Co 2+ dialkyl compounds. The lower oxophilicity and presumed greater functional-group tolerance of late transition metals relative to early metals make them promising targets for the development of catalysts suitable for the preparation of ethylene and polar vinyl monomer copolymers which are currently industrially prepared by radical polymerization. [2] This and further applications in the hydrofunctionalization of olefins and functionalized olefins, such as hydrogenation of germinal and 1,2-disubstituted alkenes will be reported. [1] Zhu, D.; Janssen, F.F.B.J.; Budzelaar, P.H.M. Organometallics 2010, 29, [2] a) Johnson, L. K.; Mecking, S.; Brookhart, M. J. Am. Chem. Soc. 1996, 118, 267; b) Mecking, S.; Johnson, L. K.; Wang, L.; Brookhart, M. J. Am. Chem. Soc. 1998, 120,

42 Polynuclear transition metal compounds made with ILs Fanni Falk, Alexander Hinz and Martin Köckerling Inorganic Solid State Chemistry, Institute of Chemistry, University Rostock Albert-Einstein-Str. 3a, Rostock Poster Since more than a decade ionic liquids (ILs) have encountered increasing attentions as starting materials and reaction media. It is a fact that new polynuclear transition metal compounds can be obtain with ionic liquids. 8 Our Group has succeeded in synthesing new compounds by adding transition metal salts to ILs. Thereby the metals salts were limited to acetates with a paddle wheel structure. Already new polynuclear copper(ii), chromium(ii) and rhodium(ii) acetate compounds were obtain using ionic liquids with the 1-butyl-3-methyl imidazolium (BMIm) cation and halogenides or pseudohalogenids as anions, for example chloride or thiocyanate. [1] In these compounds the dimere acetate structure was preserved. However in one compound it was possible to gain chains with altering paddle wheel acetates as shown below. [2] Therefore our interest is to further investigate these structures. It is our goal to obtain new structures by expanding our research to other transition metal salts and other ionic liquids. Figure 2 Part of the (BMIm)[Cu 2(OAc) 5] [Cu(OAc) 2(H 2O)] 2 structure. [1] A. Hinz, diploma thesis, University Rostock, Germany, [2] A. Hinz, M. Köckerling, Z. Anorg. Allg. Chem. 2015, 641,

43 Selective Oxidation of Hexaphenylhexaazatrinaphtylene (HATNPh6) mixed valent Titanium complex Pia Fangmann, Aleksandra Markovic, Marc Schmidtmann, Gunther Wittstock, Rüdiger Beckhaus* Institute of Chemistry, Carl von Ossietzky University Oldenburg, D Oldenburg Poster The tris-chelating nitrogen heterocyclic molecule 1,4,5,8,9,12- hexaazatriphenylene (HAT) and its homologues were often studied in the context of their coordination modes to metal ions, photo physical properties, liquid crystalline ordering, light harvesting systems and chirality. [1,2] The structure and electrochemistry of the titanium complex of the hexamethyl derivative of 1,6,7,12,13,18-hexaazatrinaphthylene (HATNMe6) is known and discussed. [3,4] Our new example HATNPh6 titanium complex shows a better solubility and show the accessibility of ten oxidation states. The first three oxidations states (II-IV) are synthesized by using ferrocenium salts as oxidizing agents. The resulting cations are fully characterized including single X-ray diffraction and mass spectrometry. 9 To clarify the ways of oxidations solid state structures, mass spectra, NIR-spectra, cyclic voltammograms and magnetic properties of species I-IV are shown and discussed. [1] S. Kitagawa, S. Masaoka Coord. Chem. Rev. 2003, 246, [2] J. L. Segura, R. Juarez, M. Ramos, C. Seoane Chem. Soc. Rev. 2015, 44, [3] I. M. Piglosiewicz, R. Beckhaus, W. Saak, D. Haase, J. Am. Chem. Soc. 2005, 127, [4] I. M. Piglosiewicz, R. Beckhaus, G. Wittstock, W. Saak, D. Haase, Inorg. Chem. 2007, 46,

44 Covalent - organic frameworks based on silicon precursors Felix Feige (a), Matthew Addicoat (b), Thomas Heine (b), Enno Lork (a), Lars Robben (a), Jens Beckmann (a)* (a) Institut für anorganische Chemie und Kristallographie, Universität Bremen; (b)wilhelm- Ostwald-Institut, Universität Leipzig (a) Leobener Str. 7, Bremen; (b) Philipp-Rosenthal-Straße 31, Leipzig felixfeige@gmx.de Poster Covalent - organic frameworks (COFs) have became an important substance group in catalytic [1] and gas saving [2] applications because of their immense inner surface. This work is about the formation of tetrahedral organosilanes via catalytic condesations reaktions, which formed a network of covalent bounded secondary building units. Calculations predicted networks with an inner surface area of more than 8500 m²/g BET. For this synthesis Tetrasilanol (4) had been made by reaction of H-Silane (3) with water catalyzed by Palladium (II) [3]. After this 4 had been polycondesated under formation of thermal high stable siloxane bonds [4]. TGA/DSC analyses showed a thermal stability until 500 C of siloxane [1] S. Y. Ding, J. Gao, Q. Wang, Y. Zhang, W. G. Song, C. Y. Su and W. Wang, J. Am. Chem. Soc. 2011, 133, [2] X. Feng, X. Ding and D. Jiang, Chem. Soc. Rev. 2012, 41, [3] J. Beckmann, D. Dakernieks, A. Duthie and R. C. Foitzik, Silicon Chemistry 2003, 2, [4] J. Beckmann, A. Duthie, G. Reeske and M. Schürmann, Organometallics 2005, 24,

45 Design and Synthesis of non-porphyrin based LD-CISSS Complexes for Switchable MRI Contrast Agents Kim Fischer, Hannah Brandenburg, Felix Tuczek* Institut für Anorganische Chemie, Christan-Albrechts-Universität zu Kiel Max-Eyth-Str. 2, Kiel Poster LD-CISSS (Light-Driven Coordination-Induced Spin State Switching) is one of the lightinduced spin switching mechanisms. [1] By isomerization of a photoswitchable ligand the coordination number of the metal ion changes which leads to a spin transition between the high spin state and the low spin state. In case of nickel(ii) switching between the low spin and the high spin complex implicates a change between diamagnetic and paramagnetic. Such LD- CISSS systems are suitable candidates for switchable contrast agents for MRI. [2] We developed the first non-porphyrin based Ni(II) systems which show coordination-induced spin-state switching (CISSS). Ni(II) salpn complexes were investigated via Evans-NMR, UV/vis and 19 F-NMR titration experiments. By determination of association constants and thermodynamic parameters for the coordination of axial ligands to unfunctionalized Ni(II) complexes a prediction of the switching behaviour of analogous LD-CISSS systems is possible. [3] 11 [1] S. Venkataramani, U. Jana, M. Dommaschk, F. D. Sönnichsen, F. Tuczek, R. Herges, Science 2011, 331, [2] M. Dommaschk, M. Peters, F. Gutzeit, C. Schütt, C. Näther, F. D. Sönnichsen, S. Tiwari, C. Riedel, S. Boretius, R. Herges, J. Am. Chem. Soc. 2015, 137, [3] H. Brandenburg, B. Schwager, K. Fischer, B. Flöser, J. Krahmer, C. Näther, F. Tuczek, manuscript in preparation Kiel

46 Fünfring bleibt Fünfring Synthese von η 4 -Iminkomplexe des Titans und deren ungewöhnliche Reaktivität Malte Fischer, Marc Schmidtmann, Rüdiger Beckhaus* Institut für Chemie, Carl von Ossietzky Universität Oldenburg, D Oldenburg, Deutschland ruediger.beckhaus@uni-oldenburg.de Im Zuge unserer Untersuchungen bezüglich der Koordination von Iminen an ein Titanzentrum wurden η 1 - und η 2 -Koordinationsmodi gefunden, z. T. begleitet von McMurry- und Aldolartigen C C-Kupplungsreaktionen. [1,2] Für Ketimine I mit aromatischen Resten wird die verkappte, azabutadienartige η 4 -Koordination beobachtet (1). [2] Unterstützt wurde diese neuartige Koordinationsform eines Imins an ein Metallzentrum durch experimentelle und theoretische Studien sowie Einkristallröntgenstrukturanalysen (s. 1b). [2] Während klassische Monoazadienkomplexe des Titans (II) (R 3 und R 4 nicht cyclisch miteinander verbunden) Ringerweiterungsreaktionen mit Carbonylverbindungen oder Nitrilen zu den korrespondieren Siebenringen (III) eingehen [3a,b], reagieren die Komplexe 1a und 1b überraschend wie Titanaaziridine (IV) unter Rearomatisierung des vorher koordinierenden Arylrestes (rot markiert) zu fünfgliedrigen Titanacyclen (s. 2a). Auf Grundlage dieser Ergebnisse wurden umfangreiche Reaktivitätsstudien von 1a und 1b angeschlossen. Es werden die vollständig charakterisierten Reaktionsprodukte der verkappten Titanaazabutadienkomplexe 1a und 1b mit Carbonylverbindungen, Alkinen, Iminen, Heterocumulenen, Allylverbindungen und Lithiumamiden vorgestellt, in denen ein Reaktionsschema klar überwiegt: Fünfring bleibt Fünfring! 12 [1] F. Loose, M. Schmidtmann, R. Beckhaus, Z. Anorg. Allg. Chem. 2017, 643, [2] F. Loose, I. Plettenberg, D. Hasse, W. Saak, M. Schmidtmann, A. Schäfer, T. Müller, R. Beckhaus, Organometallics 2014, 33, [3] a) M. Manßen, laufende Dissertation , b) J. Scholz, S. Kahlert, Organometallics 1998, 17,

47 Dinitrogen activation by a chromium PNP-pincer complex Maximilian Fritz, Christian Würtele, Sven Schneider* Institute for Inorganic Chemistry, Georg-August University Tammannstraße 4, Göttingen maximilian.fritz@uni-goettingen.de Poster 13 Group 6 pincer complexes attracted a lot of attention in the context of nitrogen fixation. In contrast to molybdenum, chromium complexes with strongly activated N2-ligands are scarce as a consequence of reduced metal to N2 back bonding and the generally higher stability of high spin states. [1] Chromium dinitrogen complexes reported in the literature commonly occur in low oxidation states and are stabilized by multidentate, rigid ligands like polyphosphines, [2-4] diiminepyridine, [5] or nacnac. [6] We here present the first example of a dinuclear, square planar coordinated chromium(ii/ii) complex with a linearly bridging dinitrogen ligand. The N2-moiety exhibits strong activation (DNN = 1.21 Å). The synthesis, electronic structure and reactivity are discussed. [1] N. C. Smythe, R. R. Schrock, P. Müller, W. W. Weare, Inorg. Chem. 2006, 45, [2] M. T. Mock, A. W. Piermont, J. D. Egbert, M. O Hagan, S. Chen, R. M. Bullock, W. G. Dougherty, W. S. Kassel, R. Rousseau, Inorg. Chem. 2015, 54, [3] M. T. Mock, S. Chen, R. Rousseau, M. O Hagan, W. G. Dougherty, W. S. Kassel, D. L. DuBois, R. M. Bullock, Chem. Commun. 2011, 135, [4] J. D. Egbert, M. O Hagan, E. S. Wiedner, R. M. Bullock, N. A. Piro, W. S. Kassel, M. T. Mock, Chem Commun. 2016, 52, [5] I. Vidyaratne, J. Scott, S. Gambarotta, P. H. M. Budzelar, Inorg. Chem. 2007, 46, [6] W. H. Monillas, G. P. A. Yap, L. A. MacAdams, K. H. Theopold, J. Am. Chem. Soc. 2007, 129,

48 Tuning the basicity of siloxane systems Malte Fugel, Maxie F. Hesse, Rumpa Pal, Jens Beckmann, Dylan Jayatilaka, Peter Luger, Wolfgang Morgenroth, Amir Karton, Graham Chandler, Patrick Bultinck, Michael J. Turner, Simon Grabowsky* Institut der anorganischen Chemie und Kristallographie, Universität Bremen Leobener Straße NW2, 28359, Bremen Poster The oxygen linkage in siloxane systems (R3Si-O-SiR3) exhibits only a low basicity which makes electrophilic attacks and the formation of hydrogen bonds unfeasible. We present hightly accurate theoretically obtained hydrogen bond energies of disiloxane-water ((H3Si)2O...HOH) and disiloxane-silanole ((H3Si)2O...HOSiH3) complexes with the Si-O-Si angle fixed at varying values starting from 103. It is found that hydrogen bonding is becoming increasingly unfeasible as the Si-O-Si angle becomes more linear until no stable hydrogen bond complexes are obtained for angles greater than 168, which is in accordance with previous studies by Grabowsky et al. [1,2] Weinhold et al. have shown that strong hyperconjugative interactions of LP(O) σ*(si-x) type account for the low siloxane basicity. [3,4] The decreasing siloxane basicity may accordingly be attributed to the increase of these interactions with an increase in the Si-O-Si angle. In order to get a grasp at how the electronic situation changes as the Si-O-Si angle increases, both natural bond orbital and real space bonding indicators (Quantum Theory of Atoms in Molecules, electron localizibility indicator) are applied to analyze the bonding situation in disiloxane (H3Si-O-SiH3) model systems with the Si-O-Si angle fixed at varying values between of 105 and 180. All indicators show that the Si-O bond is becoming more polarized as the Si-O-Si angle is becoming more linear. At the same time, the extend of the hyperconjugative interactions is increasing, which shows that ionic and covalent interactions may increase simultaneously. The same analysis is performed for n-membered cyclic siloxane systems (Si2H4O(CH2)n-3; n = 3, 4, 5), whose optimized geometries show much smaller Si-O- Si angles the oxygen atom in these molecules is therefore inherently more basic. [1] S. Grabowsky, M. F. Hesse, C. Paulmann, P. Luger, J. Beckmann, Inorganic Chemistry 2009, 48, [2] S. Grabowsky, J. Beckmann, P. Luger, Australian Journal of Chemistry 2011, 30, [3] F. Weinhold, R. West, Organometallics 2013, 135, [4] F. Weinhold, R. West, Journal of the American Chemical Society 2013, 135,

49 15 Coordination-Noninnocent Behavior of Antimony Ligands Sinas Furan, Enno Lork, Jens Beckmann* Institut für Anorganische Chemie und Kristallographie, Universität Bremen Leobener Straße, Bremen, Germany Poster Historically antimony-based ligands have been considered to mirror the same chemical behavior of their lighter phosphorus-based congeners. However evidence is growing that antimony-based ligands may display a unique coordination behavior and reactivity.[1] Several research groups reported about their noninnocent behavior and, unlike their lighter phosphine and arsine analogues, they tend to form relatively labile complexes when coordinated to transition metals.[2-4] This can be correlated to the moderate donicity of the antimony-based lone pair, which bears a large 5s character.[2] Up to now, despite the diverse Lewis acid and redox chemistry that antimony exhibits, there have only been limited efforts to explore this chemistry regarding the coordination sphere of a transition metal interaction.[1] Currently we aim to understand and exploit these effects that occur in a metal complex bearing an antimony-based ligand. [1] J. Stuart Jones, F. P. Gabbaї, Acc. Chem. Res. 2016, 49, [2] C. R. Wade, F. P. Gabbaї, Angew. Chem., Int. Ed. 2011, 50, [3] N. R. Champness, W. Levason, Coord. Chem. Rev. 1994, 133, [4] M. Jimenez-Tenorio, M. C. Puerta, I. Salcedo, P. Valerga, I. D. Rios, K. Mereiter, Dalton Trans. 2009,

50 From Diaminoacetylenes to Cyclic Bent Allene Ligands L. Hackl, A.R. Petrov, M.Freytag, M.Tamm* Institut für Anorganische und Analytische Chemie, TU Braunschweig Hagenring 30, Braunschweig Poster Diaminoacetylenes have been known since 1964 when first synthesized by Viehe.[1] However, only a few applications of these highly electron-rich alkynes in organometallic chemistry have been reported over the years.[2] In 2010, a novel synthetic protocol for the preparation of diaminoacetylenes has been developed by our group, allowing for a more convenient synthesis of, e.g., dipiperidinoacetylene[3] which has been used in the synthesis of a variety of organometallic compounds, mostly focusing on its dicarbenoid character.[4] Herein, we report the dimerisation of dipiperidinoacetylene yielding the enyne 1 under thermal conditions. This enyne can be reacted with different main group and transition metal precursors, yielding complexes with a cyclic bent allene ligand, a class of ligands for which only few examples exist.[5] 16 Scheme 1. Reactions of enyne 1. [1] H. G. Viehe, M. Reinstein, Angew. Chem. 1964, 76, 537. [2] see references in [3]. [3] A. R. Petrov, C. G. Daniliuc, P. G. Jones, M. Tamm, Chem. Eur. J. 2010, 16, [4] e.g. A. R. Petrov, T. Bannenberg, C. G. Daniliuc, P. G. Jones, M. Tamm, Dalton trans. 2011, 40, ;[1] H. Kelch, S. Kachel, M. A.Celik, M. Schäfer, B. Wennemann, K. Radacki, A. R. Petrov, M. Tamm, Chem. Eur. J. 2016, 22, [5] e.g. V. Lavallo, C. A. Dyker, B. Donnadieu, G. Bertrand, Angew. Chem. Int. Ed. 2008, 47, 5411.; M.Melaimi, P. Parameswaran, B. Donnadieu, G.Frenking, G. Bertrand, Angew. Chem. Int. Ed. 2009, 48,

51 Synthesis and characterization of POCOP, POCSP & PSCSP Ni pincer complexes and their application in catalysis Patrick Hasche, Anke Spannenberg, Torsten Beweries* Leibniz-Institute for Catalysis at the University of Rostock Albert-Einstein-Straße 29a, Rostock Poster Pincer ligands have become ubiquitous in organometallic chemistry.[1] The transistion metal complexes featuring POCOP type pincer ligands represent a group with interesting properties as complexes of Ni and Pd based on these ligands are known to be effective catalysts for the reduction of carbon dioxide,[2] Suzuki coupling[3] and the hydrosilylation of aldehydes[4]. Following our interest in the development of pincer chemistry, we report the synthesis and characterization of new pincer ligands and complexes by changing one or both oxygen atoms between the aromatic ring and the phosphorus donor atoms with sulfur atoms. We successfully modified a recently published direct, one-pot synthesis[5] for our sulfur containing compounds and tested our new Ni pincer complexes towards their catalytic activity in the Kumada cross coupling reaction with good results. 17 [1] A. S. Goldman, M. Brookhart, A. H. Roy MacArthur, J Choi, Chem Rev. 2011, 111, [2] H. Guan, S. Chakraborty, J. A. Krause, Z. Zhang, J. Am. Chem. Soc. 2010, 132, [3] D. Morales-Morales, J. M. Serrano-Becerra, S. Hernandez-Ortega, Inorg. Chim. Acta 2010, 363, [4] H. Guan, S. Chakraborty, J. A. Krause, Organometallics 2009, 28, [5] D. Zargarian, B. Vabre, F. Lindeperg, Green Chem. 2013, 15,

52 Synthese von Kupfer(II)-Komplexen mit flexiblen und starren Bis(2-benzimidazol)-Liganden und ihre biologische Aktivität: DNA-Bindung und DNA-Spaltung Julian Heinrich, Niklas König, Sebastian Sobottka, Biprajit Sarkar, Nora Kulak* Institut für Chemie und Biochemie, Freie Universität Berlin Fabeckstr. 34/36, Berlin Poster Hier beschreiben wir die Synthese sowie spektroskopische, strukturelle und elektrochemische Charakterisierung von Kupfer(II)-Komplexen mit verbrückten Bis(2-benzimidazol)- Liganden.[1][2] Die biologische Aktivität der Kupfer(II)-Komplexe wurde hinsichtlich der Art der Verbrückung untersucht. Im Vergleich zeigt der Kupfer(II)-Komplex mit einer flexiblen Ethylen-Brücke im Liganden-Rückgrat eine höhere DNA-Spaltaktivität als der Komplex mit einer starren ortho- Phenylen-Brücke. Dabei liegt ein oxidativer DNA-Spaltmechanismus zugrunde und es konnte gezeigt werden, dass die Nukleaseaktivität mit der DNA-Bindung korreliert. 18 [1] G.A. van Albada, W.J.J. Smeets, N. Veldman, A.L. Spek, J. Reedijk, Inorg. Chim. Acta 1999, 290, [2] Y.-Y. Deng, F.-Q. Lui, Y.-L. Jin, Transition Met. Chem. 2012, 37,

53 Proximity Enforced Agostic Interactions Involving Closed-Shell Coinage Metal Ions Sebastian Holsten(a), Emanuel Hupf(a), Lorraine A. Malaspina(a), Enno Lork(a), Valeri Kozich(b), Karsten Heyne(b), Stefan Mebs(b)*, Simon Grabowsky(a)*, Jens Beckmann(a)* (a) Institut für anorganische Chemie und Kristallographie, Universität Bremen, Loebener Straße 7, Bremen (b) Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, Berlin Poster In the past, coinage metal cluster recieved interest for catalysis and could be used in a broad formation with high activity and selectivity.[1] Cu(I) and Ag(I) have a d10-closed-shell spherical outer core and shows a high affinity to Si-H-bond activation.[2,3] To research the interactions between M(I)-compounds and Si-H-bonds our workgroup synthesized bis(5- diphenylphosphinoacenaphth-6-yl)methylsilane and added metal chloride (Cu, Ag) (scheme 1). The resulting crystals were investigated by neutron-diffraction-experiments to show the agostic interaction between the metal centre and the silicon-hydride bond. 19 [1] M. Joost, S. Mallet-Ladeira, K. Miqueu, A. Amgoune, D.Bourissou, Organometallics 2013, 32, [2] W. Scherer, P. Meixner, J. Barquera-Lozada, C. Hauf, A. Obenhuber, A. Brück, D. Wolstenholme, K. Ruhland, D. Leusser, D. Stalke, Angew. Chem. Int. Ed. 2013, 52, [3] H.-Suh, D.Balcells, A. Edwards, L. Guard, N. Hazari, E. Mader, B. Mercado, M. Repisky, Inorg. Chem. 2015, 54,

54 20 Charge Density Analysis of Cobalt(II) phosphate Helena Keil, Regine Herbst-Irmer, Dietmar Stalke* Institute for Inorganic Chemistry, Georg-August-University Göttingen Tammannstraße 4, 37077, Göttingen Poster Cobalt phosphate can be applied as a catalyst in the oxidative dehydrogenation of ethane and propane [1] as well as in the oxidation of water in the presence of solar light [2] to name just a few examples. In order to learn more about the properties of cobalt phosphate and to make an attempt to understand its catalytic effect, an experimental charge density analysis was made. Suitable crystals were obtained from the melt and high resolution x-ray diffraction data up to 0.3 Å were collected on an in-house Ag source. After structure refinement based on the Hansen- Coppens multipole model [3] the charge density distribution as analysed according to Bader s Quantum Theory of Atoms in Molecules (QTAIM) [4]. The first hint of the catalytic activity of only one of the two Co atoms in the asymmetric unit was found in the fact that they have different coordination geometries and electron density distributions (see fig. 1). VSCCs (valence shell charge concentrations) around the Co atoms are shown. They correspond to the maxima ED-concentration around the metal and therefore correlate to the maxima occupied d- orbitals. Due to the high resolution, it was also possible to analyse the d-orbital population of the Co atoms. Figure 3: Laplacian around Co1 (left) and Co2 (right) on the contour level of eå -5. [1] A. Aaddane, M. Kacimi, M. Ziyad, Catalysis Letters, 2001, 73, [2] M. W. Kanan, J. Yano, Y. Surendranath, M. Dinca, V. K. Yachandra, D. G. Nocera, J. Am. Chem. Soc, 2010, 132, [3] N. K. Hansen, P. Coppens, Acta Crystallogr. 1978, A34, [4] R. F. W. Bader, Atoms in Molecules: A Quantum Theory. 1990, Oxford. 50

55 Selective Catalytic Reduction of NOx by NH3 Using V/Ce1-xFexO2-δ-type Catalysts Sonja Keller, Jabor Rabeah, Ursula Bentrup, Giovanni Agostini, Hanan Atia, Angelika Brückner* Leibniz-Institut für Katalyse Albert-Einstein-Straße 29a, Rostock Poster The selective catalytic reduction of nitric oxides by ammonia using vanadium based catalysts is a wellestablished process for the treatment of exhaust gas in stationary sources. However, the applicability of the known catalysts is limited to a relatively narrow operational window ( C). For use in nonstationary applications like diesel or lean-burn engines, the catalysts must be active at reaction temperatures below 300 C. Doping of ceria with zirconia and titania has shown to increase the oxygen storage capacity (OSC) of the catalysts and therefore leads to higher activities in the SCR process. [1] In this work, the NH 3-SCR of NO x by vanadia-impregnated and Fe-doped ceria has been investigated. Catalysts were characterised by XRD, H 2-TPR and Raman-Spectroscopy. To study the reactive centres by in situ-ftir spectroscopy, MeOH and NO have been used as probe molecules. Moreover, in situ DRIFTS and EPR measurements have been performed to derive structure-reactivity relationships under reaction conditions. Iron forms a solid solution with ceria, when the Fe-content does not exceed 5%. Higher Fe percentages lead to the segregation of antiferromagnetic Fe xo y clusters, which might be a reason for the unselective combustion of NH 3 above 280 C (Fig. 1). For the V-free supports, activity rises with increasing Fe content. Though impregnation with vanadia generally leads to higher activity compared to the bare supports, activity decreases with rising V content (Fig. 1). In situ EPR and DRIFTS measurements suggest that the introduction of FeO x-species hinders an effective V 4+ /V 5+ -redox shuttle which was found to be catalytically important for other V/Ce 1-xM xo 2-δ catalysts with M=Zr or Ti [1]. In conclusion it could be shown that iron has a beneficial effect on the catalytic activity of the bare supports but the formation of FeO x-agglomerates might lead to decreasing activity in the VO x-impregnated catalysts. 21 Figure 4: NOx and NH3 conversion of the bare supports and V-impregnated catalysts at 150 to 300 C [1] Vuong, T.H., Radnik, J., Kondratenko, E., Schneider, M., Armbruster, U., Brückner, A., Appl.Catal.B 2016, 197,

56 Temperature-dependent structural and spectroscopic investigations on (Bi1-xFex)FeO3 22 A.Kirsch, M. M. Murshed, M. Kirkham, A. Huq, F. J. Litterst, Th. M. Gesing * Institut für Anorganische Chemie und Kristallographie, Universität Bremen Leobener Straße /NW2, 28359, Bremen a.kirsch@uni-bremen.de Poster Multiferroic BiFeO 3 and Bi 2Fe 4O 9 show interesting properties [1, 2], depending on their respective crystal chemistry [3] and crystallite/particle dimensionality [4, 5]. In spite of intense studies, some of their complex properties are not completely understood even in single crystals and bulk materials especially in the case of BiFeO 3 [6]. A recent temperature-dependent study suggested the existence of (Bi 1-xFe x)feo 3 perovskite-type structure [7]. The iron occupancy on the perovskite A-site changed during heating, starting from a X-ray amorphous nanocrystalline powder [7]. The present study reports on two samples with x = 0.15 and The samples were produced using a sol-gel route and subsequent heating at 873 K. Temperature-dependent neutron time-of-flight powder diffraction were carried out at POWGEN (SNS, Oak Ridge) from 10 K to 650 K, Raman spectroscopy from 78 K to 710 K, 57 Fe Mössbauer spectroscopy from 20 K to 300 K and X-ray powder diffraction at 11-BM (APS, Argonne). Several structural parameters were followed with temperature. A superparamagnetic behavior of the samples with a magnetic saturation of M s = 7.31 emu/g at 50 koe was revealed by 57 Fe Mössbauer as well as SQUID measurements. Temperature-dependent phonon decay helped understand to distinguish between the quasiharmonic and the anharmonic contributions to some selective modes. [1] F. Huang, et al., Sci. Rep. 2013, 3, [2] S. Sun, et al., J. Phys. Chem. C 2009, 113, [3] A. Palewicz, et al., Acta Cryst. B 2007, 63, [4] A. Jaiswal et al., J. Phys. Chem. C 2010, 114, [5] Q. Zhang, et al., J. Phys. Chem. C 2011, 115, [6] G. Catalan and J.F. Scott, Adv. Mater. 2009, 21, [7] A. Kirsch, et al., Z. Naturforsch. B 2016, 71,

57 23 Derivate des 1,6,7,12-Tetraazaperylens Matthias Kirste, Thomas Brietzke und Hans-Jürgen Holdt* Universität Potsdam, Institut für Chemie Karl-Liebknecht-Straße 24-25, Haus 26, Raum 1.78, Golm Poster 1,6,7,12-Tetraazaperylen (tape) ist ein neuer großflächiger, redoxaktiver Brückenligand. Wir konnten mit tape mono-, homodi- sowie heterodinukleare Metall-Komplexe synthetisieren und durch Röntgenkristallstrukturanalyse, UV/Vis-Spektroskopie und Cyclovoltammetrie charakterisieren.[1-3] Für die Synthese oligonuklearer 3d- und 4f-Metallkomplexe mit neuen magnetischen Eigenschaften haben wir uns das Ziel gesetzt, Derivate von tape zu synthetisieren, mit denen die Eigenschaften von tape-metallkomplexen, einschließlich ihrer Redoxpotentiale, modifiziert werden können. Analog der tape-synthese konnten wir das 2,11- Dimethyl- (dmtape) und 2,5,8,11-Tetramethyltape (tmtape) darstellen. Außerdem fanden wir, dass sich koordiniertes[4] und freies tape mit Sulfit-Anionen zum 3,10-Disulfonatotape (dstape) umsetzen lässt. Erste Versuche zur Reaktivität des dstape ergaben, dass es mit Natriummethanolat zum 3,10-Dimethoxytape (dmeotape) umgewandelt werden kann. [1] T. Brietzke, W. Mickler, A. Kelling, H.-J. Holdt, Dalton Trans. 2012, 41, [2] T. Brietzke, W. Mickler, A. Kelling, U. Schilde, H.-J. Krüger, H.-J. Holdt, Eur. J. Inorg. Chem. 2012, 29, [3] T. Brietzke, A. Kelling, U. Schilde, W. Mickler, H.-J. Holdt, Z. Anorg. Allg. Chem. 2016, 642, [4] T. Brietzke, H.-J. Krüger, H.-J. Holdt, submitted. 53

58 Phosphorus Bisylides: A New Class of Superbases with Two Interacting Carbon Atoms as Basicity Centers Kögel, J. F.; a,b Margetić, D.; c Kovačević, B.; c Xie, X.; b Finger, L. H.; b Sundermeyer, J. b* a FB Biologie/Chemie, Universität Bremen; b FB Chemie, Philipps-Universität Marburg; c Ruđer Bošković Institute, Zagreb 24 koegel@uni-bremen.de, jsu@staff.uni-marburg.de Poster Classical proton sponges (such as DMAN shown in Figure 1) are known for their extraordinary basicity based on the spacial proximity of two basic nitrogen centers. [1] The unexpectedly high pkbh + values can be referred to the unfavorable repulsion of the nitrogen atoms lone pairs as well as the formation of a hydrogen bond between the basicity centers after protonation. The most basic representatives are bisphosphazenes which exhibit two interacting Schwesinger bases (see HMPN in Figure 1). [2] Noticing the intrinsically higher basicity of ylides compared to phosphazenes, we designed MHPN bearing two ylidic entities attached to a naphthalene backbone in 1,8-position. [3] And indeed, with a pkbh + value of 33.3 in acetonitrile solution, MHPN is by more than a thousand times more basic than its bisphosphazene analog HMPN (pkbh + (MeCN) = 29.9). However, the basicity enhancement compared to the corresponding monoylide is based on principles completely different to those previously found for nitrogen based proton sponges. Instead of forming a hydrogen bond after protonation, a fast proton exchange between the two ylidic carbon centers is observed in MHPN s monoprotonated form. This phenomenon is studied by NMR spectroscopic methods, XRD analysis and theoretical calculations. Figure 1. The first proton sponge DMAN was reported by Alder in [1] HMPN is an example of a bisphosphazene proton sponge. [2] The bisylide MHPN is the subject of our work published recently. [3] The picture on the right illustrates the proton hopping process between the basicity centers after monoprotonation. [1] Bowman, P. S.; Steele, W. R. S.; Winterman, D. R.; Alder, R. W.; Chem. Commun. 1968, [2] Raab, V.; Gauchenova, E.; Merkoulov, A.; Harms, K.; Sundermeyer, J.; Kovačević, B.; Maksić, Z. B.; J. Am. Chem. Soc. 2005, 127, [3] Kögel, J. F.; Margetić, D.; Xie, X.; Finger, L. H.; Sundermeyer, J.; Angew. Chem. 2017, 129, ; Angew. Chem. Int. Ed. 2017, 56,

59 25 Alles wird besser" - Eine Sicherheitsbelehrung Dr. Jan Krahmer, Sicherheitsbeauftragter Institut für Anorganische Chemie, CAU Kiel Max-Eyth-Straße 2 D Kiel jkrahmer@ac.uni-kiel.de Poster Wie alles begann: Jeder Student und Mitarbeiter eines chemischen Institutes muss sich mindestens einmal im Jahr einer Sicherheitsunterweisung unterziehen. Anfangs haben wir dafür den Sicherheitsfilm Alles wird gut von der Universität Erlangen verwendet. Die Grundlage zu dem neuen Film bildet die Broschüre Sicherheit im chemischen Hochschulpraktikum und Technische Regeln für Gefahrstoffe für Laboratorien TRGS526.[1] Matthias Burmeister hat es dann geschafft unsere Ideen dazu in ein vernünftiges Drehbuch zu verwandeln. Er hat auch den Kontakt zu NDR-Sprecher Norbert Radzanowski hergestellt und war für Kamera und Schnitt zuständig. Die Übersetzung: "General Laboratory Safety" Safety instructions, produced by students and staff of the Institute of Inorganic Chemistry at Kiel University. "General Laboratory Safety" provides safety information on handling hazardous substances in chemistry labs. [1] publikationen.dguv.de/dguv/pdf/10002/i-8553.pdf 55

60 Application of combined in-situ luminescence and X-ray diffraction analyses for monitoring energy transfer during crystallization of emissive complexes Patric Lindenberg, Niklas Ruser, Niclas Heidenreich, Sebastian Leubner, Anna-Maria Tsirigoni, Huayna Terraschke* Institute of Inorganic Chemistry, University of Kiel Max-Eyth-Straße 2, 24118, Kiel Poster Lanthanide (Ln) ions e.g. Eu 3+ and Tb 3+ are known for their strong light emission [1] and are particularly interesting for the in-situ luminescence analysis of coordination sensors (ILACS) [2] due to their spectroscopic sensitivity to the coordination environment. [3] The objective of this work is therefore to introduce the energy transfer (ET) between Tb 3+ and Eu 3+ as well as from the organic ligand to the Ln 3+ ions as an additional tool for monitoring the formation of emissive complexes, for instance, Tb(phen)2(NO3)3:Eu 3+ (phen = 1,10-phenanthroline). The addition of the phen to the Tb 3+ ( mol%) and Eu 3+ ( mol%) solutions causes the change of the green luminescence (Fig. 1) assigned to the 5 D4 7 F3-6 Tb 3+ electronic transitions (Fig. 2) to the red emission characteristic of the 5 D0 7 F0-4 Eu 3+ transitions, due to ET processes during the formation of Tb(phen)2(NO3)3:Eu 3+. Interestingly, these changes in the emission properties are already identified for the complex in solution, prior to the crystallization process detected by in-situ X-ray diffraction (XRD) analysis at DESY (Fig. 3). 26 Fig. 1: Changes in emission properties during synthesis of Tb(phen) 2(NO 3) 3:Eu 3+. Fig. 2: In-situ luminescence spectra recorded during synthesis of Eu 3+ -doped Tb(phen) 2(NO 3) 3. Fig. 3: Comparison between in-situ luminescence and XRD intensities during synthesis of Eu 3+ -doped Tb(phen) 2(NO 3) 3, measured at P09. [1] K. Binnemans, Chem. Rev. 2009, 109, [2] H. Terraschke, L. R. Arana, P. Lindenberg, W. Bensch, Analyst, 2016, 8, [3] C. Zhu, S. Chaussedent, S. Liu, Y. Zhang, A. Monteil, N. Gaumer, Y. Yue, J. Alloys Compd. 2013, 555,

61 27 Redox-Isomerism in a dinuclear, donor-alkyne-bridged complex Stephan Ludwig, Kai Helmdach, Alxander Villinger and Wolfram W. Seidel* Universität Rostock Institut für Chemie, Albert-Einstein-Straße 3a, Rostock stephan.ludwig@uni-rostock.de Poster Redox isomerism is a well established phenomenon in coordination chemistry. [1] It can involve the transfer of an electron from a metal center to one of its ligands, or vice versa, thereby changing the oxidation state of the metal in question by ±1. Alternatively, metal-metal redox isomerism has also been described, oftentimes in CN-bridged systems. [2] This kind of isomerism is frequently called valence tautomerism, even though such a process should involve the rearrangement of chemical bonds.. Herein, we present a set of two dinuclear complexes in which W(II) and Ru(II) centers are bridged by an alkyne unit bearing one phosphine- and one thiolate-function. (For information on α-donor-substituted alkynes, see [3], [4].) We were able to separate two isomers which were shown to be epimers by X-ray-analysis, exhibiting significant differences in the structure of the complex core. Surprisingly, upon treatment with 1e-oxidizing agents, one isomer shows a W- centered and the other a Ru-centered oxidation. This unusual behaviour has been proven by a number of spectroscopic tools. [1] R. Buchanan, C. Pierpont*, J. Am. Chem. Soc. 1980, 102,15, [2] O. Sato*, J. Tao, Y-Z. Zhang, Angew. Chem. Int. Ed. 2007, 46, [3] W. Seidel*, M. Meel, M. Schaffrath, T. Pape, Eur. J. Org. Chem. 2007, [4] K. Helmdach, S. Ludwig, A. Villinger, D. Hollmann, J. Kösters, W. Seidel*, Chem. Commun. 2017, 53,

62 28 Halogen Stabilised Silyl Cations Anastasia Merk, Thomas Müller* Institute of Chemistry, Carl von Ossietzky University Oldenburg Carl-von-Ossietzky-Str. 9-11, D Oldenburg, European Union Poster Silyl cations are strong Lewis acids and found beneficial applications in catalysis and in bond activation reactions. Therefore the Lewis acidity can be influenced by an electron donating group and as a consequence the reactivity of the silyl cations can be tuned. [1] Here we report the syntheses of two silyl borates 2,3 [B(C6F5)4], where the positive charged silicon atoms are intramolecularly stabilised by electron donation from halogen substituents. We noticed a different reactivity between both halonium ions 2. In addition, we found that the halonium ions 2 undergo an intermolecular aryl-alkyl exchange reaction to form the siliconium ions 3. [2-4] Scheme 2 Hydride transfer reaction of silanes 1 with trityl borate. [1] H. F. T. Klare, M. Oestreich, Dalton Trans. 2010, 39, [2] K. Müther, P. Hrobárik, V. Hrobáriková, M. Kaupp, M. Oestreich, Chem. Eur. J. 2013, 19, [3] A. Schäfer, M. Reißmann, A. Schäfer, W. Saak, D. Haase, T. Müller, Angew. Chem. Int. Ed. 2011, 50, [4] A. Schäfer, M. Reißmann, S. Jung, A. Schäfer, W. Saak, E. Brendler, T. Müller, Organometallics 2013, 32,

63 29 Lanthanide-Containing Tungstogermanates Ali S. Mougharbel, Saurav Bhattacharya, Bassem S. Bassil, and Ulrich Kortz* Jacobs University, Department of Life Sciences and Chemistry, Campus Ring 1, Bremen Polyoxometalates (POMs) are discrete, anionic metal-oxides and they can be considered as soluble fragments of extended metal oxides, which are of tremendous importance in catalysis. POMs have a large variety of shape, size and structure accompanied by manifold properties resulting in potential applications in many areas such as catalysis, magnetism, medicine and materials science. [1] The family of tungstogermanates is an important subclass of POMs and the most commonly used precursors are the monolacunary [α-gew11o39] 8- and the trilacunary [α- GeW9O34] 10-, [2] as well as the dilacunary [γ-gew10o36] 8-. [3] Many lanthanide-containing POMs have been reported over the years and some exhibit interesting magnetic, photochromic and Lewis acidic properties. [4] In 2007, our group reported the synthesis and structural characterization of the monolanthanide-containing polyanion family [Ln(β2-SiW11O39)2] 13- (Ln = La, Ce, Sm, Eu, Gd, Tb, Yb, Lu). [5] Here we report on the synthesis and structural characterization of several Ge-analogues with the formula [Ln(β2- GeW11O39)2] 13-, which were characterized in the solid state by single-crystal XRD, IR, and TGA. [1] (a) M. T. Pope, Heteropoly and Isopoly Oxometalates, Springer Verlag, (b) M. T. Pope, A. Müller, Angew. Chem. Int. Ed. 1991, 30, (c) M. T. Pope, U. Kortz, Encyclopedia of Inorganic and Bioinorganic Chemistry, [2] G. Hervé, A. Tézé, Inorg. Chem. 1977, 16, [3] N. H. Nsouli, B. S. Bassil, M. H. Dickman, U. Kortz, B. Keita, L. Nadjo, Inorg. Chem. 2006, 45, [4] (a) B. S. Bassil, U. Kortz, Z. Anorg. Allg. Chem. 2010, 636, (b) T. Yamase, M. T. Pope, Polyoxometalate Chemistry for Nano-Composite Design, Springer, [5] B. S. Bassil, M. H. Dickman, B. von der Kammer, U. Kortz, Inorg. Chem. 2007, 46,

64 Organoantimony-Containing Polyoxometalates for Biomedical Applications Nickolet Ncube, Tian Ma, and Ulrich Kortz* Jacobs University Department of Life Sciences and Chemistry, Campus Ring 1, Bremen Poster Polyoxometalates (POMs) are discrete, anionic metal-oxo compounds with unmatched structural variety and unprecedented applications in catalysis, magnetism, materials science and biomedicine. 1 POMs with covalently attached organic groups are of particular interest as such functionalization allows for fine-tuning of lipophilicity, stability, solubility as well as redox properties. Coupling the features of organic groups with the chemical robustness of the inorganic polyanion opens doors for interesting and specialized applications in biomedicine. Our work in the area of polyanions functionalized by organoantimony groups started in 2009 when we reported the synthesis of the phenylantimony(v)-containing 18-tungsto-2-phosphate [{PhSb(OH)}3(A-a-PW9O34)2] This polyanion proved to be highly solution-stable, which motivated us to further develop this class of hybrid organic-inorganic POMs. Over the years we have prepared several new members including POMs containing phenylantimony(iii) as well as functionalized phenylantimony(iii) groups. 3 Surprisingly, all these POMs were solution-stable and even at physiological ph conditions. Therefore, we performed biological studies, with a focus on antibacterial activity. We were even able to establish structure-activity relationships. Here we give an overview of our work in this area. [1] (a) M. T. Pope, Heteropoly and Isopoly Oxometalates, Springer, Berlin, (b) M. T. Pope, U. Kortz, Encyclopedia of Inorganic and Bioinorganic Chemistry, 2012 [2] L. F. Piedra-Garza, M. H. Dickman, O. Moldovan, H. J. Breunig, U. Kortz, Inorg. Chem. 2009, 48, [3] (a) P. Yang, Z. Lin, B. S. Bassil, G. Alfaro-Espinoza, M. S. Ullrich, M.-X. Li, C. Silvestru, U. Kortz, Inorg. Chem. 2016, 55, (b) P. Yang, Z. Lin, G. Alfaro-Espinoza, M. S. Ullrich, C. I. Rat, C. Silvestru, U. Kortz, Inorg. Chem. 2016, 55, (c) P. Yang, B. S. Bassil, Z. Lin, A. Haider, G. Alfaro-Espinoza, M. S. Ullrich, C. Silvestru, U. Kortz, Chem. Eur. J. 2015, 21, (d) M. Barsukova-Stuckart, L. F. Piedra-Garza, B. Gautam, G. Alfaro-Espinoza, N. V. Izarova, A. Banerjee, B. S. Bassil, M. S. Ullrich, H. J. Breunig, C. Silvestru, U. Kortz, Inorg, Chem. 2012, 51,

65 Synthese von alternativen Präkursoren zur synthetischen Darstellung von mono-sulfid-bis-dithiolen Molybdänkomplexen 31 Ricardo Nowack*, Carola Schulzke Institut für Biochemie, Ernst-Moritz-Arndt-Universität Greifswald Felix-Hausdorff-Straße 4, Greifswald Poster Einige Enzyme, z.b. Sulfurtransferase, sind sowohl an der Synthese von FeS-Clustern sowie an der Herstellung der Dithiolengruppe des MoCo (Molybdän-Cofaktors) beteiligt.[1] Ein organisches Ligandensystem zur Bindung des Molybdäns in MoCo ist Molybdopterin (MPT) welches das Metallion mittels eben dieser Dithioleneinheit bindet.[2-4] Chemische Modelle des MoCo müssen die Bindungseinheit des MPT berücksichtigen und die Koordinationsphäre imitieren. Zusätzlich zum MPT-Liganden wird das Metallion durch einen Oxo- oder Sulfidoliganden koordiniert. Die Mimetik von MPT-verwandten Ligandensystemen und einem Sulfidoliganden stellt eine besondere Herausforderung dar. Um die Rolle des Sulfidoliganden zu entschlüsseln, synthetisieren wir Dithiolenkomplexe mit funktionellen Gruppen, die den MoCo nachahmen. Insbesondere suchen wir nach neuen Synthesewegen, um mono-sulfido- Komplexe zu synthetisieren. Eine Möglichkeit dies zu erreichen, wäre die Verwendung des sulfidanalogen Vorläuferkomplexes des Tetracyanodioxomolybdats, welcher jedoch noch unbekannt ist. Eine oxo-analoge Synthese dieses Ausgangsmaterials war bisher nicht erfolgreich weshalb wir nun vor allem verschiedene Wege ausgehend von homoleptischen Cyanokomplexen untersuchen (Abbildung 1).[5] [1] K. Yokoyama, S. Leimkühler, Biochimica et Biophysica Acta (BBA) Molecular Cell Research 2015, 1853, [2] R. Hille, J. Hall, P. Basu, Chem. Rev. 2014, 114, [3] R. Eisenberg, E. I. Stiefel, R. C. Rosenberg, H. B. Gray, J. Am. Che. Soc. 1966, 88, [4] E. I. Stiefel, R. Eisenberg, R. C. Rosenberg, H. B. Gray, J. Am. Chem. Soc. 1966, 88, [5] G. Krüss, Liebigs Ann. Chem. 1884, 29,

66 Towards the Versatile N-functionalisation of Unsymmetrical Diborane(4) Derivatives Wiebke Oschmann, Christian Kleeberg* Institut für Anorganische und Analytische Chemie Hagenring 30, Braunschweig Poster Recently Kleeberg et al. established unsymmetrical diborane(4) compounds as precursors for diaminoboryl complexes.[1,2] The unsymmetrical diborane(4) derivatives used were obtained by N-functionalisation of the parent compound dabb Bpin (dab = 1,2-diaminobenzene, pin = pinacolato), via formal double deprotonation, followed by reaction with a suitable electrophile. However, the scope of suitable electrophiles is limited to reactive ones, e. g. methyl iodide, benzyl bromide or trimethylsilyl chloride (Figure, I).[1] In order to expand the scope of this procedure we investigated the deprotonation of dabb Bpin in greater detail. Our findings indicate that, while simple on paper, the deprotonation of dabb Bpin to the single and the twofold deprotonated species is possible but a number of side-products, intermediates and equilibria are crucial in this reaction. Moreover, investigation of a variety of bases indicates that, depending on the basicity and nucleophilicity of the individual bases, the formation of deprotonation products as well as Lewis Acid/Base adducts is observed.[3] As a second diborane(4) cat*b Bdab (cat* = 3,5-di-tert-butylcathechol) was studied (Figure, II).[3] Understanding the properties and, in particular, reactivity of the (double) deprotonated diborane(4) species towards electrophiles should give access to a broader variety of unsymmetrical diborane(4) derivatives as boryl ligand precursor and make this valuable class of ligands more accesible. 32 [1] C. Borner, C. Kleeberg, Eur. J. Inorg. Chem. 2014, [2] C. Borner, K. Brandhorst, C. Kleeberg, Dalton Trans. 2015, 44, [3] W. Oschmann, C. Kleeberg, unpublished data. 62

67 Diversification of Polyoxometallates: The structure of [{Ni(cyclam)}2V15Sb6O42] Philipp Polzin, Christian Näther, Wolfgang Bensch Institute of Inorganic Chemistry, Christian-Albrechts-Universität of Kiel, Max-Eyth-Str. 2, Kiel, Germany. Polyoxovanadates (POVs) are remarkable materials with possible application as e.g. catalyst or sensors due to their attractive chemical and physical properties. [1] Some POVs are suitable for the hydrogen/oxygen evolution reactions or degrade organic dyes and are stable under different conditions like air, heat and light. [1] The functionality of the POVs results from their variability of crystal structures, compositions and in some cases novel and unusual connection modes. [1] In this work, a new POV and its structure are presented. The precursor cluster {Ni(en)3}3[V15Sb6O42(H2O)x] n H2O (n 15) [2] (en = ethylendiamine) reacts with [Ni(cyclam)](ClO4)2 (cyclam = 1,4,8,11-tetraazacyclotetradecane) under hydrothermal conditions yielding the new compound with the formula [{Ni(cyclam)}2V15Sb6O42]. The compound was characterized by single crystal X-ray diffraction and crystallizes in the trigonal space group R3c with 18 unique [V15Sb6O42] clusters per unit cell (Fig. 1). The Ni 2+ ion in the [Ni(cyclam)] 2+ complex is surrounded by the cyclam molecules in a square planar coordination and additionally covalently bonded to two oxygen atoms of two neighbouring clusters, which leads to the formation of a 3D structure. 33 Fig. 5: Unit cell of the new compound [{Ni(cyclam)} 2V 15Sb 6O 42] with 18 unique [V 15Sb 6O 42] clusters (displayed as polyeder). [1] K. Y. Monakhov, W. Bensch, P. Kögerler, Chem. Soc. Rev., 2015, 44, [2] M. Wendt, U. Warzok, C. Näther, J. van Leusen, P. Kögerler, C. A. Schalley, W. Bensch, Chem. Sci., 2016, 7,

68 Synthesis, Structure and Catalysis of Peroxo-Ce IV -Containing Heteropolytungstates 34 Muhammad Qasim, Bassem S. Bassil, and Ulrich Kortz* Department of Life Sciences and Chemistry, Jacobs University, Campus Ring 1, Bremen Poster Discrete metal-oxo clusters known as polyoxometalates (POMs) exhibit a large diversity in their structural and compositional aspects resulting in a variety of properties suitable for applications in different fields such as catalysis, magnetism, material science and biomedicine. 1 Several peroxo-containing POMs are known and some are highly active in oxidation catalysis, such as the Venturello ion ([PW4O8(O2)8] 3- ). In 2008 we reported a trimeric, cyclic 6-peroxo- 6-zirconium(IV) containing 30-tungsto-3-silicate, [Zr6(O2)6(OH)6(γ-SiW10O36)3] Two years later we reported on a family of dimeric, peroxo-containing heteropolytungstates, [M2(O2)2(XW11O39)2] 12- [M = Zr 4+, X = Si, Ge; M = Hf 4+, X = Si] and their oxidation catalysis. 3 Here we report on the synthesis and structural characterization of the peroxo-ce IV -containing heteropolytungstates {Ce6(O2)9X3W30} (X = Si, Ge), which represent the first examples of peroxo-lanthanide POMs. These compounds were characterized in the solid state by singlecrystal XRD, IR, TGA, and elemental analysis. As the polyanions are solution-stable they were also studied as homogeneous oxidation catalysts. 1. M. T. Pope, U. Kortz, Polyoxometalates. In Encyclopedia of Inorganic and Bioinorganic Chemistry; R. A. Scott, Ed.; John Wiley: Chichester, B. S. Bassil, S. S. Mal, M. H. Dickman, U. Kortz, H. Oelrich, L. Walder, J. Am. Chem. Soc. 2008, 130, (a) S. S. Mal, N. H. Nsouli, M. Carraro, A. Sartorel, G. Scorrano, H. Oelrich, L. Walder, M. Bonchio, U. Kortz, Inorg. Chem. 2010, 49, 7. (b) C. Jahier, S. S. Mal, U. Kortz, S. Nlate, Eur. J. Inorg. Chem. 2010, 10, (c) M. Carraro, N. Nsouli, H. Oelrich, A. Sartorel, A. Sorarù, S. S. Mal, G. Scorrano, L. Walder, U. Kortz, M. Bonchio, Chem. Eur. J. 2011, 17,

69 Tuning the Optoelectronic Properties of Stannoles Isabel-Maria Ramirez y Medina, Markus Rohdenburg, Farzin Mostaghimi, Simon Grabowsky, Petra Swiderek, Jens Beckmann, Vincent Dorcet, Muriel Hissler, Jonas Hoffmann, Anne Staubitz* Institute for Organic and Analytical Chemistry, University of Bremen Leobener Str. NW2C 7, 28359, Bremen ramirez-y-medina@uni-bremen.de Poster Stannoles are organometallic heteroaromatic rings whose aromaticity is not based on the classical Hückel criteria, but on π*-σ* conjugation.[1,2] The formal replacement of C by Sn in cyclopentadienes leads to unique optoelectronic properties in comparison to their carbon analogs. Stannoles show smaller energy gaps between the HOMO and LUMO and broad bathochromically shifted absorption maxima.[3] In this work, the influence of different substituents at the Sn or in the periphery of the ring on the optoelectronic properties has been studied both experimentally and theoretically. Calculations of optimized equilibrium geometries, energy gaps between HOMO and LUMO and absorption spectra of a wide range of compounds were performed. The computational data showed that the change of the substituents at the Sn atom influences the optoelectronics to a much lower extent than substituents in the 2 and 5-positions of the ring. Compounds with a planar backbone showed in general much better electronic properties than twisted structures. A series of six selected, novel stannoles was synthesized by formation of a zirconium intermediate and subsequent transmetalation to obtain the desired compound. Crystal structures, UV-Vis spectra and cyclic voltammetry measurements were compared with the theoretical results.[4] 35 [1] M. Saito, Coord. Chem. Rev. 2012, 256, [2] V. Y. Lee, A. Sekiguchi, Angew. Chem. Int. Ed. 2007, 46, [3] S. Yamaguchi, K. Tamao, Bull. Chem. Soc. Jpn. 1996, 69, [4] I.-M. Ramirez y Medina, M. Rohdenburg, F. Mostaghimi, S. Grabowsky, P. Swiderek, J. Beckmann, V. Dorcet, M. Hissler, J. Hoffmann, A. Staubitz, Manuscript in preparation. 65

70 36 Luminescence tuning of a new scandium coordination polymer Pia Rönfeldt, Huayna Terraschke, Martin Albat and Norbert Stock* Institut für Anorganische Chemie, Christian-Albrechts-Universität, Max-Eyth-Straße 2, D Kiel proenfeldt@ac.uni-kiel.de Poster Due to their use as sensors, light emitting diodes (LEDs), high-resolution laptop displays, lasers or for medical imaging luminescent materials have attracted considerable attention. [1] A promising class of crystalline luminescent materials are presented by coordination polymers and metal-organic frameworks, because the wide variety to combine inorganic building units and organic linker molecules enables the possibility to design luminescence. [2] Herein we report the structure and luminescence properties of a hydrothermally synthesized scandium coordination polymer [Sc2(H2O)(TATB)2] based on 4,4,4 -s-triazine-2,4,6-triyl-tribenzoic acid (H3TATB) as linker molecule (Fig.1 a). X-ray crystallographic analysis reveals that the Sc(III) coordination polymer crystallizes in the orthorhombic space group Fddd. In the crystal structure the organic linker molecules appear in a pairwise arrangement that indicates π-πstacking (Fig.1 b). [3] The scandium-based compound shows a linker-based luminescence, which can be strongly influenced by doping with lanthanide ions like Eu 3+ and Tb 3+. Using different molar ratios of trivalent lanthanide ions during synthesis allowed the fine tuning of the emitting color of the phosphor. Thus emission light was modulated from green to red, over yellow and different orange shades (Fig.1 c). [4] Fig. 1: a) 3D framework of the scandium coordination polymer, b) pairwise arrangement of the linker molecules with a distance of Å, c) : [Sc 2(H 2O)(TATB) 2] doped with different concentrations of Eu 3+ and Tb 3+ ions by daylight (top) and under UV-Light (λ = 365 nm, bottom). [1] T. Jüstel, H. Nikol, C. Ronda, Angew. Chem. Int. Ed. 1998, 37, [2] J. Heine, K. Müller-Buschbaum, Chem. Soc. Rev 2013, 42, [3] H. Zhang, N. Li, C. Tian, T. Liu, F. Du, P. Lin, Z. Li, S. Du, Cryst. Growth Des. 2012, 12, 670. [4] H. Terraschke, Less material, more energy: Synthesis of novel nanostructured luminescent materials, Universität Siegen,

71 Monitoring 5d-4f electronic transitions during synthesis of Ce(L)2(NO3)3 (L = 2,2 -bipyridine, 1,10-phenanthroline) Laura Ruiz Arana, Jonas Ströh, Patric Lindenberg, Hajer Said, Marvin Radke, Niclas Heidenreich, César dos Santos Cunha, Sebastian Leubner, Huayna Terraschke* Institute of Inorganic Chemistry, University of Kiel Max-Eyth-Straße 2, 24118, Kiel hterraschke@ac.uni-kiel.de Poster Applying the in-situ luminescence analysis of coordination sensors (ILACS) method, we aim to acquire information about desolvation processes, crystal growth rate, induction time [1-2] during synthesis of [Ce(L)(NO3)3] (L = 1,10-phenanthroline (phen), 2,2 bipyridine (bipy)) complexes. The experimental procedure consists of a simplified co-precipitation method adding the respective ligand (phen and bipy) to a Ce(NO3) 6H2O ethanolic solution. For instance for the [Ce(phen)2(NO3)3] complex, the in-situ luminescence measurements presented initially a broad band emission at nm (Fig. 1), assigned to the 5d-4f Ce 3+ ions within the ethanolic solvation shell. Upon the addition of phen, we observed a red shift to nm, ascribed to the changes in the environment of the Ce 3+, indicating its desolvation and incorporation to the [Ce(phen)2(NO3)3] complex, confirmed by in-situ infrared (IR) measurements. Additionally, in-situ X-ray diffraction (XRD) measurements performed at the DESY synchrotron facility corroborate the induction time of 3 min, coinciding with the ILACS results. Moreover, for [Ce(bipy)2(NO3)3], the induction time is strongly affected by the concentration of the solutions. Increasing three times the initial concentration of the Ce 3+ and bipy solutions caused the reduction of the induction time from 8 to 4 min. Monitoring and controlling the influence of the reaction parameters on the structure of emissive complexes are important for the development of rational synthesis approaches and optimization of structure-related properties such as luminescence. 37 Figure 1: Ex-situ emission spectra of Ce 3+ in ethanol and after incorporation into the [Ce(phen) 2(NO 3) 3] complex at λ ex = 400 nm (left). Commission Internationale d`eclairage CIE 1931 chromaticity diagram plot of the color coordinates of the Ce 3+ in ethanolic solution ( ) and of [Ce(phen) 2(NO 3) 3] ( ) (right). [1] H. Terraschke, M. Rothe, P. Lindenberg, Rev. Anal. Chem. 2017, accepted. 67