Hofmann type clathrates – spectroscopic studies of the low frequency region

Abstract

A series of Hofmann type clathrates with a general formula: M(NH 3) 2M′(CN) 4·2G, where M ∈ {Ni, Mn, Cd}, M′ ∈ {Ni, Pd}, while G is benzene or thiophene, were prepared and their Raman and far-infrared spectra were recorded in the region 650–50 cm −1. The main bands of the vibrational spectra in the low frequency region were assigned to the stretching and deformational vibrations: ν(Ni–C)/ ν(Pd–C), δ(NiCN)/ δ(PdCN), π(NiCN)/ π(PdCN), δ(CNiC)/ δ(CPdC), ν(M–N) and δ(NMN) originating from the host lattices: M(NH 3) 2Ni(CN) 4 or M(NH 3) 2Pd(CN) 4. The Raman and far-infrared spectra of the studied Hofmann type clathrates were compared with the corresponding spectra of K 2Ni(CN) 4 and K 2Pd(CN) 4 as well as with Ni(NH 3) 6Cl 2, and in some cases, with the spectra of the “empty” clathrates.