Synthesis and reactivity of new trimethylplatinum(IV) complexes containing chiral Schiff bases as ligands: Crystal structure of (OC-6-44-C)-[PtIMe3{κ2-(R)-Ph2P(C6H4)CHNC*H(Ph)Me-P,N}]

Reaction of the tetranuclear complex [PtIMe3]4 with the ligand (S)- and (R)-Ph2P(C6H4)CHNC*H(Ph)Me in a 1:4 molar ratio yields the mononuclear neutral complexes in diastereoisomeric mixtures [PtIMe3{κ2-Ph2P(C6H4)CHNC*H(Ph)Me-P,N}]. Iodide abstraction from mixture with AgBF4 in the presence of pyridine (Py) induces a reductive elimination reaction with loss of ethane, leading to the cationic complex [PtMe(Py){κ2-Ph2P(C6H4)CHNC*H(Ph)Me-P,N}][BF4] [C* = (S)-, 3; (R)-, 4]. When this reaction was carried out in the presence of PPh3 a consecutive orthometallation reaction with loss of methane is produced, forming the cationic complex [Pt(PPh3){κ3-Ph2P(C6H4)CHNC*H(C6H4)Me-C,P,N}][BF4], [(S)-, 5; (R)-, 6]. All species were characterised in solution by 1H and 31P{1H} NMR spectroscopy, elemental analysis and mass spectrometry.The crystal structure of the diastereoisomer (OC-6-44-C)-[PtIMe3{κ2-(R)-Ph2P(C6H4)CHNC*H(Ph)Me-P,N}] has been determined by single-crystal X-ray diffraction.

Graphical abstractThe synthesis and characterisation of new neutral complexes in diastereomeric mixtures of formula [PtIMe3{κ2-Ph2P(C6H4)CHNC*H(Ph)Me-P,N}] are described. The crystal structure of the diastereoisomer (OC-6-44-C)-[PtIMe3{κ2-(R)-Ph2P(C6H4)CHNC*H(Ph)Me-P,N}] is determined by single-crystal X-ray diffraction methods. The treatment of the mixture with pyridine, in the presence of AgBF4, yields a reductive elimination reaction. The similar reaction with PPh3 involves a consecutive orthometallation reaction.Figure optionsDownload full-size imageDownload as PowerPoint slide