Platinum(II) complexes with dithiolates and phosphinites as ligands: Crystal structure of [Pt{S2CO}{P(OMe)Ph2}2]

Article abstract of DOI:10.1016/0277-5387(95)00261-P

Reaction of the complex [PtCl{P(O)Ph₂}{P(OH)Ph₂}₂] with silver or thallium derivatives of dithiolate ligands led to neutral complexes of general formula [Pt{S - S}{P(O)Ph₂}{P(OH)Ph₂}], where {S - S}^- = {S₂CNEt₂}^- (1), {S₂P(OEt)₂}^- (2) and [S₂COEt]^- (3). Complexes 2 and 3 reacted with an excess of NaI in acetone solution by dealkylation of the coordinated dithiolate ligand and formation of the compounds [Pt{S₂P(O)(OEt)}{P(O)Ph₂}{P(OH)Ph₂}]Na (4) and [Pt{S₂CO}{P(O)Ph₂}{P(OH)Ph₂}] Na (5), respectively. The corresponding tetraphenylphosphonium derivatives (6, 7) were prepared by a metathetical reaction of these complexes with Ph₄PBr in acetone solution. Related dithiolate complexes were obtained by reaction of the complex [Pt{S - S}₂] with P(OMe)Ph₂ in molar ratio 1 : 2. Thus, the reaction of [Pt{S₂COEt}₂] in dichloromethane solution at room temperature gave [Pt{S₂COEt}{P(OMe)Ph₂}₂]Cl (8). This complex reacted with NaI in acetone to form the neutral compound [Pt{S₂CO}{P(OMe)Ph₂}₂] (9). When the reaction was carried out in dichloromethane at reflux temperature using [Pt{S₂P(OEt)₂}₂] as starting material, the neutral compound [Pt{S₂P(O)(OEt)} {P(OMe)Ph₂}₂] (10) was obtained. The crystal structure of the complex 9 has been determined by X-ray diffraction. The neutral complex shows a nearly square-planar coordination of the metal and a planar dithiocarbonate ligand.