The most robust and unambiguous examples of selforganizing systems are from physics, where the concept was first noted.

Transkript

1 Selbstorganisation Selbstorganisation ist das spontane Auftreten neuer, stabiler Strukturen und Verhaltensweisen (Musterbildung) in offenen Systemen. Das sind Systeme, die sich fern vom thermodynamischen Gleichgewicht befinden, die also Energie, Stoffe oder Informationen mit der Außenwelt austauschen. Ein selbstorganisiertes System verändert seine grundlegende Struktur als Funktion seiner Erfahrung und seiner Umwelt. Die interagierenden Teilnehmer (Systemkomponenten, Agenten) handeln nach einfachen Regeln und erschaffen dabei aus Chaos rdnung, ohne eine Vision von der gesamten Entwicklung haben zu müssen.

2 rdnung - Chaos

3 The most robust and unambiguous examples of selforganizing systems are from physics, where the concept was first noted. Self-organization is also relevant in chemistry, where it has often been taken as being synonymous with self-assembly. The concept of self-organization is central to the description of biological systems, from the subcellular to the ecosystem level. Sometimes the notion of self-organization is conflated with that of the related concept of emergence.

4 rinzipien der Selbstorganisation ositive und negative Rückkopplung Multiple Wechselwirkung Gleichgewicht von Erkundung und Ausbeutung

5 Self-Assembly Self-assembly is the fundamental principle which generates structural organization on all scales from molecules to galaxies. It is defined as reversible processes in which pre-existing parts or disordered components of a preexisting system form structures of patterns. Self-assembly can be classified as either static or dynamic. Static self-assembly is when the ordered state occurs when the system is in equilibrium and does not dissipate energy. Dynamic self-assembly is when the ordered state requires dissipation of energy. The most well-studied subfield of selfassembly is molecular self-assembly.

6 Molecular Self-Assembly Molecular self-assembly is the assembly of molecules without guidance or management from an outside source. There are two types of self-assembly, intramolecular self-assembly and intermolecular self-assembly. Most often the term molecular self-assembly refers intermolecular self-assembly, while intramolecular is more commonly called folding.

7 Supramolekulare Chemie Supramolecular chemistry: noncovalent bonding. Supramolecular chemistry utilizes far weaker and reversible interactions» hydrogen bonding» metal coordination» hydrophobic forces,» Electrostatic forces» van der Waals forces,» pi-pi interactions, to assemble molecules into multimolecular complexes. molecular self-assembly, molecular recognition, host-guest chemistry, mechanically-interlocked molecular architectures

8 Jean Mary Lehn

9 Wasserstoffbrücken

10 Basenpaare DA

11 Hydrophob Hydrophil: Surfactants

12 Metall- Koordination

13 i i Stacking

14

15 Molecular Self-Assembly Supramolekulare Systeme Biologie Molekulare anotechnologie

16 SAM

17 olymere Strukturen Image shows air bubbles in self-assembled polymer structure.

18

19 Disorder

20 Molekulare anotechnologie Bottom-up Aproach Smart Materials one or more properties that can be significantly altered in a controlled fashion by external stimuli, such as stress, temperature, moisture, ph, electric or magnetic iezo-kristalle, ph-sensirtive olymere, chromogene Systeme Dogmen-Wechsel: hotochrome Systeme- Molekulare Schalter Sensors Robotics Richard Feynman Whitesides, G. M. & Grzyboski, B. (2002) Science 295,

21 There is a lenty of Room at the Bottom R.. Feynman, 1959

22 Metall Thiol - Arrays

23 Spatz 2001 Hierarchical self-assembly of metal nanostructures on diblock copolymer scaffolds

24 Supramolekulare rinzipien Atome, Moleküle : Festkörper, Kristalle Flüssigkristalle Kolloide Surfactants SAM (Self assembled monolayer) Langmuir Blodgett Vesikel Mizellen Membrane Supermoleküle Clathrate Assemblies Folien

25 Molekulares Lego

26 Molekulare Erkennung: ano - Mikro

27 Molecular Recognition

28 Einschluß Verbindungen: Clathrates Crown Ether Dextrine Folien

29 Crown - Ether

30 Cyclo-Dextrine

31 Cyclo- Dextrine

32 Cyclo - Dextrine

33 Cyclo - Dextrine

34 Cyclo - Dextrine

35 Rotaxane

36 Molecular Shuttle

37

38

39 Metall-Koordination

40 Koordination

41 Ruthenium Komplexe

42 Ruthenium - Komplexe

43 Ruthenium Komplexe

44 Komplexe Systeme

45

46 Extended Structures: olymers

47

48 Liganden Bildung

49 Self-Aggregated Multiporphyrin Arrays (Formation rinciples)

50 Mutual Arrangement of Chemical Trimer (ZnE) 3 h 2 and Various Extra-ligands in Multiporphyrin Arrays HyperChem, release 4.0, semiempirical methods AM1 and M3, for clarity, c β-ethyl substituents in (ZnE) 3 h 2 are omitted hotoinduced Charge Separation Electron or Energy Transfer Depending on spectral and redox properties of interacting trimer and extra-ligand as well as temperature and solvent polarity, self-assembled complexes are capable of undergoing fast intra-complex energy migration and/or photoinduced electron transfer

51 orphyrin Arrays C u Zenkevich, CvB 2002

52 CdSe Quantum Dots

53 Titration Experiments 465 nm - CdSe: hotoluminesscence quenching Molar Ratio x + H 2 : Fluorescence increase CdSe orphyrin

54 Lego rinciple via functional Groups 1 E t E t Et 2 E t H H Et E t 4 E t E t 3 meta-pyridyl ring, (m-yr) : p-iso-propyl-phenyl ring, (iso-rh): C H -para -meta 3 -ortho H CH 3 H H H H HH HH HH CdSe ZnS

55 Selfaggregated anohybrids 1 Et Et Et Et H 2 4 H Et Et E t E t 3 meta-pyridyl ring, (m-yr) : p-iso-propyl-phenyl ring, (iso-rh): H CH 3 C H 3

56 Titration Experiments 465 nm - CdSe: hotoluminesscence quenching Molar Ratio x + H 2 : Fluorescence increase CdSe orphyrin

57 hotoluminescence Quenching of CdSe d = 3.4 nm

58 Coordination and Bonds Relative CdSeZnS Intensity D =3.4 nm n yridyls 1 or 2 yridyl-bonds ormalized ormalized molar molar Ratio Ratio x

59 CdSeZnS orphyrin Arrays H H H H CdSe ZnS H H H H CdSe ZnS D (CdSe) = 3.4 nm D (CdSe) = 4.2 nm

60

61 Quantum Dot + orphyrin: Zn Coordination bond nanocrystal, 66 CdSe core atoms 156 ZnS shell atoms organic dye: free-base porphyrin two 2-pyridil bridges self-assembly: itrogen to Zinc [Zenkewich, et al J. hys. Chem. B 109, 8679 (2005) ]