Synthesis and transition metal chemistry of a bridging diphosphinite, 1,4 bis(diphenylphosphinoxy)benzene

Diphosphinite ligand, [Ph(2)POC(6)H(4)OPPh(2)] (1), is obtained by reacting chloro diphenylphosphine, with 1,4-dihydroxy benzene in presence of triethylamine. Treatment of 1 with elemental sulfur or selenium resulted in the formation of bis(chalcogenide) derivatives, [Ph(2)(E)POC(6)H(4)OP(E)Ph(2)] (2, E = S; 3, E = Se) in almost quantitative yield. The binuclear complex [{(eta(6)-p-cymene)RuCl(2)}(2)(Ph(2)POC(6)H(4)OPPh(2))] (4) is produced in the reaction between [Ru(eta(6)-p-cymene)Cl(2)](2) and diphosphinite 1. Similarly the reaction of 1 with [Rh(COD)Cl](2) afforded a binuclear complex [{(COD)RhCl}(2)(Ph(2)POC(6)H(4)OPPh(2))] (5), whereas the macrocyclic complex [{(CO)RhCl}(Ph(2)POC(6)H(4)OPPh(2))](2) (6) is isolated in the reaction of 1 with 0.5 equiv of [RhCl(CO)(2)](2). Compound 1 on treatment with [Pd(COD)Cl(2)] or [PdCl(2)(SMe(2))(2)] in 1:1 molar ratio produced the chloro-bridged binuclear complex [{(PPh(2)O)Pd(mu-Cl)(PPh(2)OH)}(2)] (7) through P-O bond cleavage. Treatment of 1 with two equivalents of CuI in dichlormethane/acetonitrile (1:1) afforded a coordination polymer, [{Cu(2)(mu-I)(2)(Ph(2)POC(6)H(4)OPPh(2))}(infinity)] (8) in moderate yield. The binuclear complex, [{AuCl}(2)(mu-Ph(2)POC(6)H(4)OPPh(2))] (9) is obtained in the reaction of compound 1 with two equiv of AuCl(SMe(2)), where the ligand exhibits bridged bidentate mode of coordination. The molecular structures of 1-4, and 6 are determined by X-ray diffraction studies