Vibrational spectra and nuclear magnetic resonance parameters of some platinum(IV) complexes [PtX4L2] and [PtX5L]–(X = Cl, Br, or I; L = NMe3, PMe3, AsMe3, or SMe2)

Abstract

trans-[ PtX₄L₂](L = PMe₃, AsMe₃, or SMe₂; X = Cl or Br) and, except X = Br for SMe₂, cis-complexes have been isolated, together with the salts Prⁿ₄N[PtX₅L], Prⁿ₄N[PtI₅PMe₃], Prⁿ₄N[PtCl₅NMe₃], and [PtCl₃(PMe₃)₃] BF₄. The vibrational spectra of the complexes have been studied. ¹H N.m.r. measurements have been made for these and other halide derivatives which were prepared in situ but were unstable to isolation in a pure form. Values of J_PtP and δ_p have been measured by heteronuclear INDOR and, in addition, those of related platinum(II) and palladium(II) compounds are reported. Approximate values of J_PtN have been obtained from ¹H(¹⁹⁵Pt) INDOR in three cases. The spectroscopic parameters are discussed and it is concluded that variations in them are consistent with significant π-contribution to Pt–P bonding, at least in platinum(II) complexes.