Synthesis of anionic rhenium carbonyl hydrides by the ring opening of rhenium carbonyl heterocycles

Abstract

The heterocyclic rhenium–bismuth complex Re 3(CO) 12(μ-H) 2(μ-BiPh 2), 1 was obtained in 62% yield from the reaction of [Bu 4N][Re 3(CO) 12(μ-H) 2] with BiPh 2Cl at room temperature. Compound 1 was converted to the [Bu 4N] salt of the dihydrido monoanion [{HRe(CO) 4} 2(μ-BiPh 2)], 2 by reaction with [Bu 4N][OH]. The anion of 2 contains a BiPh 2 ligand bridging two HRe(CO) 4 groups. The corresponding [Bu 4N] salt of the SbPh 2-bridged monoanion [{HRe(CO) 4} 2(μ-SbPh 2)], 4 was obtained from the reaction of Re 2(CO) 8(μ-SbPh 2)(μ-H), 3 with NaBH 4 followed by precipitation with [Bu 4N]Br. The anion of 4 was converted back to 3 by treatment with H[BF 4], but no characterizable product was obtained from the treatment of 2 with H[BF 4]. The crystal and molecular structures of compounds 1, 2, and 4 were established by single-crystal X-ray diffraction analyses.