Far-infrared spectra and single-crystal reflectance spectra of some complex chlorides containing distorted MCl42– tetrahedra

Abstract

The far-i.r. spectra (40–700 cm^–1) of some complex chlorides of general formula A₂MCl₄ and A₃MCl₅(A = Rb or Cs; M = Fe, Co, Ni, Cu, and Zn) which contain distorted MCl₄^2– tetrahedra have been examined. The observed bands are assigned to internal modes of vibration associated with the MCl₄^2– tetrahedra and to lattice modes. Polarised i.r. reflectance data for oriented single crystals of Cs₂ZnCl₄ and Cs₃CoCl₅ have been obtained and the observed bands are assigned to the appropriate crystal modes.