Co-ordinatively unsaturated acetylene complexes of molybdenum and tungsten : reactions of [MCl(CF3CCCF3)2(η5-C5H5)](M = Mo or W) with octacarbonyldicobalt leading to binuclear metallacyclopentadiene complexes

Abstract

Reactions of [MCl(CF₃CCCF₃)₂(η⁵-C₅H₅)](M = Mo or W) with [Co₂(CO)₈] gave the bis(µ-alkyne) complexes [MCo(CO)₃(µ-CF₃CCCF₃)₂(η⁵-C₅H₅)] and small amounts of the complexes [M(CO)₂{η³-C₄(CF₃)₃CF₂CO}(η⁵-C₅H₅)]. The former react with CO to give metallacyclopentadiene derivatives [MCo(CO)₄{C₄(CF₃)₄}(η⁵-C₅H₅)] as a result of CO addition to the metal whereas reactions with PEt₃ give carbonyl substitution products [MoCo(CO)₂(PEt₃)(µ-CF₃CCCF₃)₂(η⁵-C₅H₅)] and [WCo(CO)(PEt₃)₂(µ-CF₃CCCF₃)₂(η⁵-C₅H₅)].