Kristallstruktur und Schwingungsspektren von Zn(NH3)4(ClO4)2 / Crystal Structure and Vibrational Spectra of Zn(NH3)4(ClO4)2

Abstract

The title compound Zn(NH3)4(ClO4)2 crystallizes in the space group F4̄3m with a = 10.240(1) Å. The crystal structure consists of tetrahedral Zn(NH3)4 cations and two nonequivalent ClO4 anions with crystallographic Td symmetry. The complex ions constitute an arrangement which is known from the Zintl phase MgAgAs. The Zn(NH3)4 cations are ccp packed with perchlorate anions in octahedral and tetrahedral voids. Whereas the ClO4 ions centered at tetrahedral holes do not interact with the other lattice components, the perchlorate ions in the octahedral voids are connected with the ammine ligands by a hydrogen bonded three-dimensional network involving all their N, H, and O atoms. The repeating unit of this network is a N4O4(μ-H)12 cube with N-H = 1.19(2) Å and O···H = 1.98(2)Å . Raman and IR spectra were recorded between 150 and 4000 cm-1. All the expected internal modes of the complex ions could be detected and assigned. The crystallographically different ClO4 anions have nearly the same vibrational spectra, only a slight splitting of two IR modes is observed