Synthesis and properties of five-co-ordinate complexes of ruthenium and osmium containing the bulky phosphine 1,2-bis(diisopropylphosphino)ethane (dippe). Crystal structure of [Ru(SPh)(dippe)2][BPh4 (original) (raw)

1997, Journal of The Chemical Society-dalton Transactions

The reaction of [RuCl 2 (dippe) 2 ] [dippe = 1,2-bis(diisopropylphosphino)ethane] with NaBPh 4 in MeOH afforded the red-brown five-co-ordinate complex [RuCl(dippe) 2 ][BPh 4 ] 1. In analogous fashion, the complex cis-[OsCl 2 (dippe) 2 ] 2, prepared by reaction of [NH 4 ] 2 [OsCl 6 ] with dippe in refluxing 2-methoxyethanol, yielded the corresponding five-co-ordinate species [OsCl(dippe) 2 ][BPh 4 ] 3 upon treatment with NaBPh 4 in MeOH. Both complexes 1 and 3 react with PhSH furnishing the five-co-ordinate benzenethiolato derivatives [Ru(SPh)(dippe) 2 ][BPh 4 ] 4 and [Os(SPh)(dippe) 2 ][BPh 4 ] 5 respectively. The crystal structure of 4 has been determined, and shows that the complex cation adopts a distorted trigonal-bipyramidal geometry. With the exception of 4, which is rigid on the NMR time-scale, the other five-co-ordinate complexes are stereochemically non-rigid, and in some instances undergo dynamic processes in solution which have been ascribed to interactions with the solvent. Whereas complexes 1 and 5 do not react with H 2 , addition of H 2 to 3 yields the dihydrogen complex trans-[OsCl(H 2 )(dippe) 2 ][BPh 4 ] 6. The reaction of 4 with H 2 afforded the known five-co-ordinate hydride complex [RuH(dippe) 2 ][BPh 4 ], formed presumably by elimination of HSPh from an unstable thiolate-dihydrogen (or