The crystal structure of bis(triphenylphosphine)-(η-cyclohexa-1,3-diene)rhenium trihydride

Abstract

Bis(triphenylphosphine)(η-cyclohexa-1,3-diene)rhenium trihydride, (Ph 3P) 2(η-C 6H 8)ReH 3 (I) crystallises in the space group C2/c with cell dimensions a 22.76(2), b 10.14(1) c 29.813(6) Å, β 97.69(8)°. The final refinement of 126 variables using 1580 non-zero reflections resulted in a final R value of 0.064. In spite of uncertainties in some of the atomic positions, the structure of I is compatible with a trihydrido diene compound with a distorted pentagonal bipyramidal configuration, rather than with a dihydrido cyclohexenyl compound having an “agostic” CH ⇌ Re interaction. The factors which govern the structure of the complexes (Ph 3P) 2(η-1,3-diene)ReH 3 are discussed.