Synthesis and crystal structure of the complex [MoW{μ-C2(C6H4Me-4)2}(CO)4(η-C5H5){η5-C9H6(COMe)-1}]: An unusual product of the reaction between [W(CC6H4Me4)(CO)2(η-5H5)] and [MoMe(CO)3(η5-C9H7)]

Abstract The compounds [W(CC 6 H 4 Me-4)(CO) 2 (η-C 5 H 5 )] and [MoMe(CO) 3 (η 5 -C 9 H 7 )] (C 9 H 7 = indenyl) react readily in toluene at 60°C to give the unusual dimetal complex [MoW{μ-C 2 (C 6 H 4 Me-4) 2 }(CO) 4 (η-C 5 H 5 ){η 5 -C 9 H 6 (COMe)-1}], which has been structurally characterised by an X-ray diffraction study. The metal-metal bond [2.976(1) A] is transversely spanned by the alkyne ligand C 2 (C 6 H 4 Me-4) 2 , formed by coupling of two carbyne fragments. The tungsten atom carries a cyclopentadienyl ring and two carbonyl groups. The molybdenum atom also has two carbonyl ligands, one of which semi-bridges the MoW bond [MoCO, 168.7(5)°]. Unexpectedly the indenyl group attached to the molybdenum centre carries a COMe substituent.