Studies in Mössbauer spectroscopy. Part 13. Iodine-129 spectra of some palladium(II) and platinum(II) iodo-complexes

Abstract

Iodine-129 Mössbauer spectra are reported for the complexes cis-[Ptl₂L₂], trans-[Ptl₂L₂], trans-[PtH(I)L₂], [MI₂(L–L)], [MI₂(L–L)₂], and A₂[Pt₂I₆][M = Pd or Pt; L, L–L = tertiary phosphine, arsine, or stibine uni- or bi-dentate ligands; A = NEt₄, C₅H₅NCH₃, or P(CH₂Ph)Ph₃]. Data for the four-co-ordinate complexes are discussed in terms of the trans and cis influences of the neutral ligands. The Mössbauer-indicated cis influence is of comparable magnitude but opposite direction to the trans influence, but neither is directly related to the conventional cis and trans influences. For [MI₂(L–L)₂] the spectra indicate weak but significant interaction of the iodide with the metal atom. The spectra of the [Pt₂I₆]^2– anions are consistent with bridged structures.