Seven-coordinate dioxygen complexes from dioxygen addition to five-coordinate σ-phenyl, isocyanide-containing derivatives of ruthenium(II) and osmium(II). Crystal structures of OS(η 2-O 2)(η 2-CPh = N p-chlorophenyl)Cl(PPh 3) 2 and Os(η 2-SO 4)(η 2-CPh = N p-chlorophenyl)Cl(PPh 3) 2

Abstract

Reaction of the hydrido complexes MHCl(CNR)(PPh 3) 3 ( 1a, M = Ru, R = p-tolyl; 1b, M = Os, R = p-tolyl; 1c, M = Os, R = p-chlorophenyl) with HgPh 2 results in formation of the five-coordinate σ-phenyl complexes MPhCl(CNR)(PPh 3) 2 ( 2a, M = Ru, R = p-tolyl; 2b, M = Os; R = p-tolyl; 2c, M = Os, R = p-chlorophenyl). These five-coordinate complexes, upon contact with dioxygen, form seven-coordinate dioxygen complexes M(η 2-O 2)(η 2-CPhNR)Cl(PPh 3) 2 ( 3a, M = Ru, R = p-tolyl; 3b, M = Os, R = p-tolyl; 3c, M = Os, R = p-chlorophenyl) in which the phenyl group has migrated onto the isocyanide ligand to form a dihapto-iminoacyl ligand. The crystal structure of 3c has been determined. The complex 3c reacts with SO 2 to form the sulphate derivative Os(η 2-SO 4)(η 2-CPhN p-chlorophenyl)Cl(PPh 3) 2 ( 4c), the crystal structure of which has also been determined. Sodium acetate reacts with 2a and 2b to form MPh(η 2-O 2CCH 3)(CN p-tolyl)(PPh 3) 2 ( 5a, M = Ru; 5b, M = Os). CO reacts with OsPhCl(CN p-tolyl)(PPh 3) 2 to form OsPhCl(CO)(CN p-tolyl)(PPh 3) 2 ( 6b) and with CN p-tolyl to give OsPhCl(CN p-tolyl) 2(PPh 3) 2 ( 7b). Reaction of 2a with CO, and migration of the phenyl group, results in formation of the dihapto-iminoacyl complex Ru(η 2-CPhN p-tolyl)Cl(CO)(PPh 3) 2 ( 8a). Treatment of 2a with CN p-tolyl, followed by addition of HCl, gives the carbene complex RuCl 2(CPhNH p-tolyl)(CN p-tolyl)(PPh 3) 2 ( 9a). The hydrido complexes 1a–1c, which are the immediate precursors of the five-coordinate σ-phenyl isocyanide complexes, are generated by reaction of the dihydrido complexes MH 2(CNR)(PPh 3) 3 ( 10a, M = Ru, R = p-tolyl; 10b, M = Os, R = p-tolyl; 10c, M = Os, R = p-chlorophenyl) with HCl.