Dynamic nuclear magnetic resonance studies of conformational changes occurring in 1,4-oxathian and 1,4-oxaselenan complexes of platinum(II) and palladium(II) halides

Abstract

The ¹H n.m.r. spectra of the complexes [MX₂L₂][M = Pd or Pt, X = Cl or Br, L = 1,4-oxathian or 1,4-oxaselenan] are temperature dependent and exhibit coalescence phenomena. The spectra are particularly well suited for total band-shape fitting studies, and it has been shown that the observed coalescence phenomena are caused by site inversion about the ligand atom rather than by ring reversal of the cyclic ligand. Thermodynamic parameters are reported for site inversion occurring at co-ordinated sulphur and selenium atoms.