Silver nitrate in silver zeolite A: three-dimensional incommensurate guest ordering in a zeolite framework.
Dalton Trans
; (19): 2368-73, 2006 May 21.
Article
en En
| MEDLINE
| ID: mdl-16688325
ABSTRACT
We report the results of a detailed examination of the occlusion of silver nitrate in silver zeolite A (AgA). The superlattice reported to occur in (AgNO3)9-AgA was found to melt at between 80 and 100 degrees C on heating and reappear when the sample was cooled down to 80 degrees C. Annealing in this temperature range and rigorous exclusion of water produced an enhancement of the superlattice peaks, which results from ordering of the contents of the zeolite cages. Peaks assigned to the superlattice were indexed with the tetragonal lattice parameters a = 17.440(5) and c = 12.398(4) A and proposed space group P4/nmm. The sharp peaks representing the lattice of the framework (a = 12.3711(5) A, Pm3m) remained largely unaffected by the guest in this compound, which was found to exhibit strong negative thermal expansion. The host and guest lattices are incommensurate with the tetragonal guest lattice being slightly larger than the cubic host in the c-direction and slightly smaller in the a- and b-directions.
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Base de datos:
MEDLINE
Idioma:
En
Revista:
Dalton Trans
Asunto de la revista:
QUIMICA
Año:
2006
Tipo del documento:
Article