Seven-coordinate thiophene-3-acetonitrile complexes of tungsten(II). Crystal structures of [WI2(CO)3{NCCH2(3-C4H3S)} 2] and [WI2(CO)3{NCCH2(3-C4H3S)} (AsPh3)]

Article abstract of DOI:10.1016/S0022-328X(98)00491-4

Reaction of [WI₂(CO)₃(NCMe)₂] with 2 equivalents of thiophene-3-acetonitrile {NCCH₂(3-C₄H₃S)} gave the crystallographically characterised complex [WI₂(CO)₃{NCCH₂(3-C₄H₃S)} ₂] (1). The structure of 1 can be described as a distorted capped octahedron with a carbonyl group in the capping position, two carbonyl groups and an iodide in the capped face and two acetonitrile ligands and an iodide in the uncapped face. Treatment of the seven-coordinate complex [WI₂(CO)₃(NCMe)₂] with an equimolar amount of L {L=AsPh₃ (2) or PPh₃ (3)} followed an in situ reaction with by one equivalent of thiophene-3-acetonitrile afforded the mixed ligand complexes [WI₂(CO)₃{NCCH₂(3-C₄H₃S)} L] {2 (crystallographically characterised) and 3}. The structure of 2 also has a capped octahedral geometry, again having a carbonyl ligand in the unique capping position.