Insertion of a phospholide unit into a metal–metal bond: Synthesis and X-ray structure of [Ru3(CO)9(μ:η1:η5-PC4H2Me2)(η1-C6H5)]

Abstract The reaction of [Ru 3 (CO) 12 ] with 3,4-dimethyl-1-phenylphosphole under mild conditions affords three derivatives which were identified by means of spectroscopic methods as the substitution compounds [Ru 3 (CO) 12− x (PhPC 4 H 2 Me 2 ) x ] ( x  = 1, 2, 3) in which the phosphole ligand acts as a tertiary phosphine bonded through the phosphorus atom. Thermolysis of the monosubstituted [Ru 3 (CO) 11 (PhPC 4 H 2 Me 2 )] in cyclohexane affords two new clusters, characterised as [Ru 3 (CO) 9 (μ 3 :η 2 :η 2 :η 2 -PhPC 4 H 2 Me 2 )] and [Ru 3 (CO) 9 (μ:η 1 :η 5 -PC 4 H 2 Me 2 )(η 1 -C 6 H 5 )], where the phosphole ring behaves as a six- and seven-electron donor ligand respectively. The reaction with [Os 3 H 2 (CO) 10 ] gives the new species [Os 3 (μ-H)(CO) 9 (μ 3 :η 1 :η 1 :η 2 -PhPC 4 H 3 Me 2 )] in which the ligand behaves as a five-electron donor.