Synthesis and Characterization of a New Family of Thermally Stable Open-Framework Zincophosphate/Arsenate Phases: M3Zn4O(XO4)3·nH2O (
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- 作者：William T. A. Harrison ; Robert W. Broach ; Robert A. Bedard ; Thurman E. Gier ; Xianhui Bu ; and Galen D. Stucky
- 刊名：Chemistry of Materials
- 出版年：1996
- 出版时间：March 1996
- 年：1996
- 卷：8
- 期：3
- 页码：691 - 700
- 全文大小：332K
- 年卷期：v.8,no.3(March 1996)
- ISSN：1520-5002
文摘
The syntheses, representative crystal structures, and someproperties of a new family ofmicroporous zincophosphate/arsenate materials, denotedM3Zn4O(XO4)3·nH2O(M = Li, Na,K, Rb, Cs, ...; X = P, As; n = ~3.5-6), arereported. All these materials are based on aflexible, anionic Zn4O(XO4)3network built up from vertex-linked tetrahedral ZnO4 andXO4units. Four ZnO4 units share a vertex, resulting innovel OZn4 centers. The use of mixedfour-coordinate anion types (XO43-,O2-) results in a number of interesting structuralandstability properties. TheM3Zn4O(XO4)3·nH2Onetwork contains only pairs of 3-rings (a spiro-5unit) and 8-rings, and no 4-rings or 6-rings: it encloses roughlyspherical cavities connectedby a three-dimensional network of 8-ring channels propagating in theorthogonal [100], [010],and [001] directions (cubic unit-cell axes). Extraframeworkcations and water moleculesoccupy these cavities and channels. These phases display typical"zeolitic" dehydration/rehydration and ion-exchange reactions with thermal stabilities up to600 
C, the highestknown for this type of open-framework Zn(P/As)O material. Theincluded guest cation (Na,Rb, K, Li, ...) has a crucial effect on crystal structure, by orderingin and modifying theconfiguration of the intercavity 8-ring channels. The crystalstructures ofRb3Zn4O(PO4)3·3.5H2O,K3Zn4O(AsO4)3·4H2O,andNa3Zn4O(PO4)3·6H2Oare presented. Crystal data: Rb3Zn4O(PO4)3·3.5H2O,Mr = 881.40, cubic, space groupF
3c (No. 219), a =15.3423(9) Å, V =3611.4(6) Å3, Z = 8,Rp = 5.12%, Rwp =6.78%, 27 parameters, 1874 data points (X-ray Rietveldrefinement).K3Zn4O(AsO4)3·4H2O,Mr = 883.63, cubic, space groupF3c (No. 219), a=15.4638(2) Å, V = 3697.9(2) Å3,Z = 8, Rp = 8.69%,Rwp = 11.42%, 24 parameters, 2124datapoints (X-ray Rietveld refinement).Na3Zn4O(PO4)3·6H2O,Mr = 739.49, trigonal, spacegroupR3c (No. 161), a = 10.7489(3)Å, 
= 60.114(2), V = 880.4(4)Å3, Z = 2, R = 2.49%,Rw =2.61%, 180 parameters, 846 observed reflections with I >3
(I) (single-crystal data).
C, the highestknown for this type of open-framework Zn(P/As)O material. Theincluded guest cation (Na,Rb, K, Li, ...) has a crucial effect on crystal structure, by orderingin and modifying theconfiguration of the intercavity 8-ring channels. The crystalstructures ofRb3Zn4O(PO4)3·3.5H2O,K3Zn4O(AsO4)3·4H2O,andNa3Zn4O(PO4)3·6H2Oare presented. Crystal data: Rb3Zn4O(PO4)3·3.5H2O,Mr = 881.40, cubic, space groupF3c (No. 219), a =15.3423(9) Å, V =3611.4(6) Å3, Z = 8,Rp = 5.12%, Rwp =6.78%, 27 parameters, 1874 data points (X-ray Rietveldrefinement).K3Zn4O(AsO4)3·4H2O,Mr = 883.63, cubic, space groupF3c (No. 219), a=15.4638(2) Å, V = 3697.9(2) Å3,Z = 8, Rp = 8.69%,Rwp = 11.42%, 24 parameters, 2124datapoints (X-ray Rietveld refinement).Na3Zn4O(PO4)3·6H2O,Mr = 739.49, trigonal, spacegroupR3c (No. 161), a = 10.7489(3)Å, = 60.114(2), V = 880.4(4)Å3, Z = 2, R = 2.49%,Rw =2.61%, 180 parameters, 846 observed reflections with I >3(I) (single-crystal data).