High versatility of 3,4-dimethyl-1-phenyl-phosphole and 3-methyl-1-phenyl-phosphole as ligands in the reaction with [Re 2(CO)8(CH3CN)2] and [Ru3(CO)12]: X-ray structures of [Re2(CO)7(1:2:2-PhPC 4H2Me2)], [Re2(CO)7(1:2:2-PhPC4H3Me)] and [Ru2(CO)4(PhPC _4H_3Me)_2]

摘要

The reaction of [Re_2(CO)_8(CH_3CN) _2] with 3,4-dimethyl-1-phenylphosphole affords three chromatographically inseparable isomers of [Re_2(CO) _8(PhPC_4H_2Me_2)_2] (1) identified by means of spectroscopic methods, in which the phosphole ligand acts as a tertiary phosphine bonded through the phosphorus atom, and the σ-π complex [Re_2(CO)_7(~1: ~2:~2-PhPC_4H_2Me _2)] (2) obtained in low yields. Thermolysis of the mixture of isomers gives (2) in good yields, while photolysis in dichloromethane at room temperature causes metal-metal bond cleavage to give [Re(CO) _4(PhPC_4H_2Me_2)Cl] (3) and [Re(CO)5Cl] (4). The reaction with 3-methyl-1-phenyl-phosphole gives only the σ-π complex [Re_2(CO)_7(~1: ~2:~2-PhPC_4H_3Me)] (5). Furthermore, the main product of the reaction of [Ru_3(CO) _(12)] with 3-methyl-1-phenyl-phosphole was [Ru_2(CO) _4(PhPC_4H_3Me)_2] (6) a sandwich type complex without metal-metal bond.