Anorganische Kristallchemie

Präsentation zum Thema: "Anorganische Kristallchemie"—  Präsentation transkript:

1 Anorganische Kristallchemie
Zeitplan 1.-4. Woche Ionenkristalle Perowskit kovalente anorganische Verbindungen Zeolithe DLS (Geometrie optimierung) intermetallische Verbindungen 5.-6. Woche Pulverdiffraktometrie 7. Woche Quasikristalle W. Steurer Woche organische Kristallchemie und B. Schweizer Strukturdatenbanken

2 Kristallchemie und Kristallstrukturdatenbanken
Pulverdiffraktometrie Einkristall Strukturanalyse Strukturanalyse mittels Pulverdaten Kristallchemie in der Strukturanalyse Modellbau Simulated annealing Evolutionäre Algorithmen FOCUS Charge flipping

3 FOCUS Zeolithe 3-dimensionale, 4-fach verknüpfte Gerüststruktur

4 FOCUS Zeolithe 3-dimensionale, 4-fach verknüpfte Gerüststruktur
Eckenverknüpfte TO4 Tetraeder

5 FOCUS Zeolithe 3-dimensionale, 4-fach verknüpfte Gerüststruktur
Eckenverknüpfte TO4 Tetraeder bekannte T-O Bindungslängen, O-T-O und T-O-T Winkel O-Si-O ˚ Si-O-Si 145˚ Si-O Å

6 FOCUS approximate unit cell contents individual minimum distances
selected reflection intensities FOCUS starting phases electron density map peak search assignment of atoms by peak height minimum distances assignment of atoms to largest fragment framework search framework classification histogram new phase set convergence? no yes

7 FOCUS AlPO-ZON a 14.548 Å b 15.301 Å c 16.629 Å Raumgruppe Pbca
approximate unit cell contents individual minimum distances selected reflection intensities FOCUS AlPO-ZON a Å b Å c Å Raumgruppe Pbca Chemische Zusammensetzung |(RF)x|[Al32P32O128] V = 3956 Å3 16 T-Atome pro 1000 Å3 3.1 Å Al - Al Al - P P - P Al - O P - O 2.6 Å 1.4 Å 1.6 Å O - O 2.3 Å 2.7 Å

8 AlPO-ZON a = 14.548 Å, b = 15.301 Å, c = 16.629 Å Pbca 10 15 20 25 30
35 40 45 AlPO-ZON a = Å, b = Å, c = Å Pbca

9 FOCUS approximate unit cell contents individual minimum distances
selected reflection intensities FOCUS starting phases electron density map peak search assignment of atoms by peak height minimum distances assignment of atoms to largest fragment framework search framework classification histogram new phase set convergence? no yes

10 Peak-Positionen und -Höhen

11 FOCUS approximate unit cell contents individual minimum distances
selected reflection intensities FOCUS starting phases electron density map peak search assignment of atoms by peak height minimum distances assignment of atoms to largest fragment framework search framework classification histogram new phase set convergence? no yes

12 Atome durch Peakhöhe und miminale Abstände zugeordnet

13 FOCUS approximate unit cell contents individual minimum distances
selected reflection intensities FOCUS starting phases electron density map peak search assignment of atoms by peak height minimum distances assignment of atoms to largest fragment framework search framework classification histogram new phase set convergence? no yes

14 Atome durch grösstes Fragment zugeordnet

15 Atome durch grösstes Fragment zugeordnet

16 assignment of atoms to largest fragment
assignment of atoms by peak height minimum distances assignment of atoms to largest fragment new phase set Elektronendichte Strukturfaktor Streufaktor berechnete Phasen gemessene Amplituden

17 FOCUS approximate unit cell contents individual minimum distances
selected reflection intensities FOCUS starting phases electron density map peak search assignment of atoms by peak height minimum distances assignment of atoms to largest fragment framework search framework classification histogram new phase set convergence? no yes

18 Gerüst-Klassifikation
Wie kann man ein Gerüst eindeutig erkennen? Coordination sequence 4 9 16 25 Loop configuration Vertex symbol 4 · 4 · 4 · 6 · 6 · 12

19 VPI-9 Chemische Zusammensetzung Original K4Rb20[Si48Zn12O120]·64H2O
NH4-ausgetauscht (NH4)24[Si48Zn12O120]·64H2O Daten Original NH4-ausgetauscht Synchrotron SNBL an ESRF SNBL an ESRF Wellenlänge Å Å Elementarzelle Raumgruppe P41212 P42/ncm a Å Å c Å Å P41212 Å

20 VPI-9 - FOCUS Input Raumgruppe P42/ncm Elementarzelle a 9.8946 Å
b Å Atome / EZ Zn (4-fach verknüpft) 12 12 Si (4-fach verknüpft) 44 48 O (brückend) minimale Abstände Zn - O 1.7 Å Zn - Si 2.9 Å Si - O 1.5 Å Zn - Zn 4.0 Å O - O 2.3 Å Si - Si 2.9 Å Reflexe Gerüst-Typen gefunden (übernacht) 1356 (ein Typ 102 Mal gefunden)

21 Histogramm der Gerüst-Typen
wahrscheinlichster Gerüst-Typ Gerüst-Typen

22 Gerüststruktur mit 7 (Si,Zn) pro asymmetrische Einheit
VPI-9 Gerüststruktur mit 7 (Si,Zn) pro asymmetrische Einheit

23 VPI-9 Rubidium Zinkosilikat VPI-9
12 Si, 3 Zn, 30 O, 9 Rb, 2 K und 3 H2O pro asymmetrische Einheit

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25 Kristallchemie und Kristallstrukturdatenbanken
Pulverdiffraktometrie Einkristall Strukturanalyse Strukturanalyse mittels Pulverdaten Kristallchemie in der Strukturanalyse Modellbau Simulated annealing Evolutionäre Algorithmen FOCUS Charge flipping

26 Charge Flipping |Fhkl(obs)| δ (ed threshold for flipping)
phase shifts for weak reflections? assign random phases electron density map flip sign of ed < δ alternative method of ab initio structure determination for single crystals introduced by Oszlanyi and Suto in 2004 algorithm - simple flow diagram, deceptively simple idea combine |Fhkl(obs)| with φhkl(calc) perturbed electron density map Fourier transform R-value (|Fhkl(calc)| vs |Fhkl(obs)| |Fhkl(calc)| φhkl(calc) Oszlányi, G. and Sütõ, A. (2004). Acta Cryst. A60, Oszlányi, G. and Sütõ, A. (2005). Acta Cryst. A61,

27 Charge Flipping (powder) |Fhkl(obs)| with overlap groups
δ (ed threshold for flipping) phase shifts for weak reflections? repartitioning after n cycles electron density histogram |Fhkl(obs)| δ (ed threshold for flipping) phase shifts for weak reflections? assign random phases new|Fhkl(obs)| electron density map flip sign of ed < δ repartition overlapping reflections superflip (powder?) features of charge flipping with powders using CF to repartition, begging the question noticed during testing that correct solution could be seen in the ed histogram use histogram matching to modify the ed map for repartitioning? learn more at Christian's poster combine |Fhkl(obs)| with φhkl(calc) perturbed electron density map |Fhkl(calc)| φhkl(calc) Fourier transform |Fhkl(calc)| φhkl(calc) R-value Fourier transform modified electron density map yes n cycles? no histogram matching

28 Histogram matching 12 Å 8 Å Electronendichte alle ¼ Å 48 x 32 x 20
5 Å Electronendichte alle ¼ Å 48 x 32 x 20 = points

29 Histogram matching Elektronendichte Werte nach Intensität ordnen
Liste in 50 Bereiche aufteilen Durchschnittsdichte pro Bereich rechnen superflip (powder?) features of charge flipping with powders using CF to repartition, begging the question noticed during testing that correct solution could be seen in the ed histogram use histogram matching to modify the ed map for repartitioning? learn more at Christian's poster typischer Zeolith Karte nach ein paar Zyklen Charge Flipping

30 Powder Charge Flipping
[Zr12P16O60(OH)4F8]

31 Powder Charge Flipping
[Zr12P16O60(OH)4F8]

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