Far-infrared spectra of four-co-ordinate planar gold(III) complexes

Abstract

A Series of gold(III) complexes of the type [Au(L)X₃](L = thioethers, triphenylphosphine, or triphenylarsine; X = Cl or Br) and trans-[Au(CN)₂(L)X](L = pyridine or [²H₅]pyridine; X = Cl or Br) have been prepared and their i.r. spectra as Nujol mulls have been recorded in the region 500–70 cm^–1. For complexes [Au(L)X₃], the metal–halogen stretching vibrations are assigned and discussed on the basis of the different trans-influence of the ligand L. For the complexes trans-[Au(CN)₂(L)X], the gold–halogen and gold–carbon stretching vibrations are assigned and compared with the corresponding vibrations in the parent ions [Au(CN)₄]^– and trans-[Au(CN)₂X₂]^–. The ν(Au–Cl) and ν(Au–Br) values for ligands trans to pyridine, are in the ranges 368–363 and 262–250 cm^–1.