Abstract
The reactions of Mo(CO)6 or W(CO)6 and of bridging N-heterocyclic ligands (L) such as pyrazine or 4,4'-bipyridine with K were studied by ESR spectroscopy in the presence of excess phosphine, phosphite or arsine ligands. In many cases, double substitution at the metals could be obsd., yielding (XR3)(CO)4M-L-M(CO)4(XR3)-. (X = P, As; R = alkyl, aryl, alkoxy; M = Mo, W). ESR study of the complexes in THF soln. revealed extensive coupling of the unpaired electron with the nuclei 1H, 13C(CO), 14N, 31P, 75As, 95.97Mo and 183W. Evidence for a cis configuration at the metals is presented, and a p*/smx* hyperconjugation model is used to account for the facile substitution of CO and for the spin transfer to the peripheral nuclei. on SciFinder(R)
Users
Please
log in to take part in the discussion (add own reviews or comments).