Vibrational spectra of halides and complex halides. Part I. Hexahalogenoplatinates

Abstract

Far-infrared (60—400 cm.^–1) and laser-Raman spectra of solid complexes M^I₂[PtCl₆] and K₂PtBr₆ are reported. Force constants are computed by use of a modified Urey–Bradley force field. The Pt–Cl bond stretching force constant decreases regularly with increase in cationic size, reaching a limiting value for large organic cations. Lattice modes due to cations show a regular mass dependence. ν₆ has been observed directly for (Ph₂l)₂[PtCl₆]. The spectra of K₂[PtCl₄Br₂] are consistent with a trans formulation.