Transition-metal complexes containing phosphorus ligands. Part IX. Triaryl phosphite derivatives of palladium(II) and platinum(II) dihalides

Abstract

An extensive series of triaryl phosphite derivatives of palladium(II) and platinum(II) dihalides, MX₂[P(OAr)₃]₂(M = Pd or Pt; X = Cl, Br, or I; Ar = phenyl, p-chlorophenyl, o-, m-, or p-tolyl), have been isolated as air-stable crystalline solids by reacting triaryl phosphites, P(OAr)₃ and, where appropriate, lithium halides, LiX, with the salts Na₂MCl₄ in ethanol or the neutral complexes MX₂(cyclo-octa-1,5-diene) in benzene solution. The new complexes have been characterised and their stereochemistry investigated by i.r. and n.m.r. spectroscopy. Palladium derivatives containing bulky tri-o-tolyl phosphite or iodide ligands were obtained as trans-isomers or cis–trans mixtures, the remaining complexes occurred predominantly as the cis-isomers. An extensive compilation of ³¹P n.m.r. data is given.