Synchronous pyramidal inversion of chalcogen atom pairs in trimethylplatinum(IV)halide complexes with dithia-and diselena-cyclopentanes. X-Ray crystal structure of [(PtIMe3)2(Me2CCH2SeSeCH2)]

Abstract

Dinuclear Pt^IVcomplexes of type [(PtXMe₃)₂(Me₂[graphic omitted]H₂)](E = S, Se, X = halogen)have been synthesised and shown by X-ray analysis to involve the cyclic ligand bridging the two Pt^IV atoms, with the Pt₂X₂ moiety adopting a highly bent geometry; ¹H n.m.r. studies have identified a relatively slow, synchronous inversion of the co-ordinated chalcogen atom pair; ΔG^‡ data for the process are in the range 66–75 kJ mol^–1, these values being, in most cases, ca. 20 kJ mol^–1 higher than for the more normal single site inversion.