Investigation of the reactivity of the phosphorus-hydrogen bond in Cp ' RuL1L2Cl complexes with diphenylphosphine ligands

Products resulting from the oxidation, chlorination, hydrolysis and ethanol ysis of Cp*Ru(PHPh2)(2)Cl (1) are described. Chlorination of the P-H bond i n 1 allowed isolation of Cp*Ru(PClPh2)(2)Cl (6) and there is spectroscopic evidence for the presence of Cp*Ru(PClPh2)(PHPh2)Cl (5). Hydrolysis of comp ounds 1 and 5 gave a dihydride complex [Cp*Ru(H)(2)(OPPh2)(POHPh2)] (13) an d cationic species [Cp*Ru(PHPh2)(3)]Cl (14) and [Cp*RuPOHPh2(PHPh2)(2)]Cl ( 15). Formation of 14 was confirmed by the synthesis of [Cp*Ru(PHPh2)(3)]OTf (14') through intermediate [Cp*Ru(MeCN)(PHPh2)(2)]OTf (16) which was obtai ned from the addition of AgOTf to 1 in MeCN solution. Reaction of (Cp*RuCl2 )(2) (12) in EtOH with two equivalents of PHPh2 gave compound 1 and ethanol ysis products Cp*Ru(POEtPh2)(PHPh2)Cl (18) and Cp*Ru(POEtPh2)(2)Cl (11), wh ile reaction of 12 with diphenylphosphine oxide (OPHPh2) led to the formati on of Cp*Ru(POHPh2)(2)Cl (7), which can either be converted to hydride comp ound Cp*Ru(H)(Cl)[(OPPh2)(POHPh2)] (10) or an aromatic ring of its coordina ted phosphine will bind to the electrophilic [Cp*Ru](+) fragment to give co mpound [Cp*Ru[mu-(eta(6)-C6H5)POHPh]Cp*Ru(POHPh2)Cl]Cl (8). Based on H-1- a nd P-31-NMR spectroscopic data, compounds with two different P-donor ligand s have also been prepared, including Cp*Ru(POHPh2)(PHPh2)Cl (9), [Cp*Ru(POH Ph2)(2)(PHPh2)]OTf (17) and Cp*Ru(POHPh2)(POEtPh2)Cl (19). According to NMR observations, a free radical mechanism is proposed for the chlorination an d oxidation reactions. Crystal structures are provided for complexes 6, 13 and 18, and a related cationic Cp complex [CpRu(POHPh2)(PHPh2)(2)]Cl (20). (C) 1999 Elsevier Science S.A. All rights reserved.