Normalkoordinatenanalyse der 35Cl/37Cl-markierten Fluoro-Chloro-Platinate(IV), Cs2[PtFnCl6-n], n = 0-6 / Normal Coordinate Analysis of the 35Cl/37Cl Labelled Fluoro-Chloro-Platinates(IV), Cs2[PtF„Cl6-n, n = 0 – 6

Abstract

Normal coordinate analyses for all compounds of the two series Cs2[PtF„35Cl6-n] and Cs2[PtF„37Cl6-n], n = 0-6, including the geometric isomers for n = 2, 3, 4 have been performed, based on a general valence force field. The excellent agreement of calculated and observed frequencies confirms the assignments of the vibrational spectra. Due to the stronger trans influence of Cl compared to F in all asymmetric F–Pt–Cl axes the Pt–Cl bonds are strengthened and the Pt–F bonds are weakened, as indicated by valence force constants for Pt–Cl approximately 20% higher, for Pt–F 20% lower, compared with the values calculated for symmetric Cl–Pt–Cl and F–Pt–F axes, respectively. The contour of the Raman line ν2 (Eg, Oh) of Cs2[PtCl6] is explained by the superposition of the calculated spectra for the six most frequent isotopomers Cs2[Pt35Cln 37Cl6-n] present in mixtures with natural abundance of Cl isotopes (75,53% 35Cl, 24,47% 37Cl) by statistical distribution on the octahedron sites.