Synthesis and reactivity of new trimethylplatinum(IV) complexes containing chiral Schiff bases as ligands: Crystal structure of (OC-6-44-C)-[PtIMe3{kappa(2)-(R)-Ph2P(C6H4)CH=NC*H(Ph)Me-P,N}]

Abstract

Reaction of the tetranuclear complex [PtIMe3](4) with the ligand (S)- and (R)-Ph2P(C6H4)CH=NC*H(Ph)Me in a 1:4 molar ratio yields the mononuclear neutral complexes in diastereoisomeric mixtures [PtIMe3{K-2-Ph2P(C6H4)CH=NC*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) {kappa(2) -Ph2P(C6H4)CH=NC*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){kappa(3)-Ph2P(C6H4)CH=NC*H(C6H4)Me-C,P,N][BF4], [(S)-, 5; (R)-, 6]. All species were characterised in solution by H-1 and P-31{H-1} NMR spectroscopy, elemental analysis and mass spectrometry.

The crystal structure of the diastereoisomer (OC-6-44-C)-[PtIMe3{kappa(2)-(R)-Ph2P(R)-Ph2P(C6H4)CH=NC*H(Ph)Me-P,N}] has been determined by single-crystal X-ray diffraction