The synthesis, molecular structure and interconversion of two novel benzene-coordinated pentaruthenium–carbido cluster isomers [Ru 5 C(CO) 12 (µ 3 : η 2 : η 2 : η 2 -C 6 H 6 )] and [Ru 5 C(CO) 12 (η 6 -C 6 H 6 )]

Two isomers of a benzene-coordinated pentaruthenium–carbido cluster, [Ru5C(CO)12(µ3 : η2 : η2:η2-C6H6)]1 and [Ru5C(CO)12(η6-C6H6)]2 have been synthesised from [Ru5C(CO)15]3 and structurally characterised by single crystal X-ray diffraction; 1 is irreversibly converted to 2 on mild thermolysis.