The synthesis and reactivity of rhenocene

Oxidation of lithiodicyclopentadienylrhenium by organic carbonyl compounds gives the complex (C₂₀H₂₀Re₂). Spectroscopic data show that this complex consists of two rhenocene fragments, {(C₅H)₅Re}, linked by a metal-metal bond, and so that it must be represented as a dimer of rhenocene, {(C₅H₅)Re}₂. Reaction of the dimer with benzyl bromide gives {(C₅H₅)₂ReCH₂C₆H₅} and {(C₅H₅₂ReBr}, while thermolysis gives the new dimeric complex {(C₅H₅)₂(C₅H₄)₂Re₂} and two equivalents of {(C₅H₅)ReH} and photolysis (λ ? 410 nm) gives [{η⁴- (C₅H₆)(C₅H₅)Re}{η⁵,η¹-(C₅H₄)(C₅H₅)Re}].