Co-ordinatively unsaturated molybdenum and tungsten acetylene complexes. The mechanisms of formation of and CO substitution in [M(η5-C5H5)(SR)(CO)(CF3C⋮CCF3]

Abstract

Reactions between [M(η⁵-C₅H₅)SR¹(CO)₃](M = W; R¹= Me, Et, or Prⁱ) and hexafluorobut-2-yne (hfb) involve initial attack at sulphur and carbonyl ligands to give [[graphic omitted]R¹)(η⁵-C₅H₅)(CO)₂] which undergo stepwise rearrangement to co-ordinatively unsaturated acetylene complexes [M(η⁵-C₅H₅)(SR¹)(CO)(hfb)]; the latter (M = Mo or W, R¹= C₆F₅) undergo associative CO substitution reactions with phosphines and phosphites (L) yielding complexes [M(η⁵-C₅H₅)(SR¹)(hfb)L].