Facile bond-forming and -breaking process at phosphorus, carbon, and oxygen centres in tungsten–cobalt complexes: X-ray crystal structures of [WCo(OH)(µ-CC6H4Me-4)(µ-PPh2)2(CO)2(η-C5H5)], [WCo(O){µ-C(C66H4Me-4)C(O)}(µ-PPh2)(CO)(PPh2H)(η-C5H5)], and the novel alkyne complex [WCo(O){µ-C(C6H4Me-4)C(OMe)}(µ-PPh2)(CO)(PPh2H)(η-C5H5)][BF4]

Abstract

Treatment of the complex [WCo₂(µ₃-CC₆H₄Me-4)(CO)₈(η-C₅H₅)] with an excess of PPh₂Cl results in cluster fragmentation and formation of the dimetal complex [WCo(Cl)(µ-CC₆H₄Me-4)(µ-PPh₂)₂(CO)₂(η-C₅H₅)] which is an important precursor to a range of related W–Co derivatives; the structures of the complexes [WCo(OH)(µ-CC₆H₄Me-4)(µ-PPh₂)₂(CO)₂(η-C₅H₅)], [WCo(O){µ-C(C₆H₄Me-4)C(O)}(µ-PPh₂)(CO)(PPh₂H)(η-C₅H₅)], and [WCo(O){µ-C(C₆H₄Me-4)C(OMe)}(µ-PPh₂)(CO)(PPh₂H)(η-C₅H₅)][BF₄] have been determined by X-ray diffraction and the latter complex exhibits an unusual alkyne bonding mode.