Infrared spectra (800–200 cm.–1) of trimethylphosphine and trimethylarsine complexes of platinum and palladium MX2L2and M2X4L2(X = Cl, Br, or I)

Abstract
The infrared spectra from Nujol mulls of complexes MX2L2 and M2X4L2(M = Pt or Pd; X = Cl, Br, or I; L = PMe3 or AsMe3) are presented for the range 800–200 cm.–1, and assignments discussed. Where possible, the solution spectra of compounds MX2L2 have also been recorded. In a number of cases where cis-isomers have been obtained in the solid state, isomerisation has been found to occur in solution. The tendency for trans-isomers to be formed in solution has been assessed to be Pt < Pd, Cl < Br < I, PMe3 < AsMe3. This, together with frequency trends, is discussed.