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]
†
Abstract
The reaction of [RuCl2(dippe)2] [dippe = 1,2-bis(diisopropylphosphino)ethane] with NaBPh4 in MeOH afforded the red-brown five-co-ordinate complex [RuCl(dippe)2][BPh4] 1. In analogous fashion, the complex cis-[OsCl2(dippe)2] 2, prepared by reaction of [NH4]2[OsCl6] with dippe in refluxing 2-methoxyethanol, yielded the corresponding five-co-ordinate species [OsCl(dippe)2][BPh4] 3 upon treatment with NaBPh4 in MeOH. Both complexes 1 and 3 react with PhSH furnishing the five-co-ordinate benzenethiolato derivatives [Ru(SPh)(dippe)2][BPh4] 4 and [Os(SPh)(dippe)2][BPh4] 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 H2, addition of H2 to 3 yields the dihydrogen complex trans-[OsCl(H2)(dippe)2][BPh4] 6. The reaction of 4 with H2 afforded the known five-co-ordinate hydride complex [RuH(dippe)2][BPh4], formed presumably by elimination of HSPh from an unstable thiolate–dihydrogen (or dihydride) complex, namely [Ru(SPh)(H2)(dippe)2][BPh4].
Please wait while we load your content...
†