The mechanisms of fluxionality of [Ir4(CO)11(PEt3)]; a reappraisal of the mechanism of carbonyl fluxionality on clusters

Contrary to previous reports, it is shown that the mechanism of fluxionality of [Ir4(CO)11(PEt3)] involves intermediates retaining bridging carbonyls, rather than a species containing only terminal carbonyl groups or an icosahedral–cube-octahedral rearrangement. Two dynamic processes were identified.