Making and breaking of carbon–carbon bonds at a di-tungsten centre: X-ray structure of [W2(CO)4{µ-η2,η2-C(O)C2(CO2Me)2}(η-C5H5)2]
Abstract
Dimethyl acetylenedicarboxylate reacts with [{W(CO)3(η-C5H5)}2] under u.v. irradiation to yield the dimetallocycle [W2(CO)4{µ-η2,η2-C(O)C2(CO2Me)2}(η-C5H5)2], which ejects CO readily to give [W2(CO)4{µ-C2(CO2Me)2}(η-C5H5)2]; in both structure, determined by X-ray diffraction, and reactivity [W2(CO)4{µ-η2η2-C(O)C2(CO2Me)2}(η-C5H5)2] is subtly different from the complexes [M2(CO)(µ-CO){µ-η1,η3-C(O)C2R2}(η-C5H5)2](M = Fe or Ru).