CRYSTAL-STRUCTURE AND VIBRATIONAL-SPECTRA OF ZN(NH3)(4)(CLO4)(2)

The title compound Zn(NH3)(4)(ClO4)(2) crystallizes in the space group F $($) over bar$$ 43m with a = 10.240(1)Angstrom. The crystal structure consists of tetrahedral Zn(NH3)(4) cations and two nonequivalent ClO4 anions with crystallographic T-d 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(mu-H)(12) cube with N-H = 1.19(2) Angstrom and O...H = 1.98(2) Angstrom. 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.