Owen Summerscales - Reductive coupling of carbon monoxide by U(iii) complexes—a computational study

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      Publication Details (including relevant citation   information):

      Dalton   Trans.   2011 40, 11080-11088


      The role of U((η-C8H6{SiiPr3-1,4}2)(η-C5Me5) and   U((η-C8H6{SiiPr3-1,4}2)(η-C5Me4H) in the reductive di- tri- and   tetramerization of CO has been modelled using density functional   methods and U(C8H8)(C5H5) as the metal fragment. The orbital   structure of U(C8H8)(C5H5) is described. CO binding to form a   monocarbonyl U(C8H8)(C5H5)(CO) is found, by a variety of methods,   to place spin density on the CO ligand via back-bonding from the   U5f orbitals. A possible pathway for formation of the yne diolate   complex [U(C8H8)(C5H5)]2C2O2 is proposed which involves   dimerization of U(C8H8)(C5H5)CO via coordination of the CO O   atoms to the opposing U atoms followed by C–C bond formation to   form a zig-zag intermediate, stable at low temperatures. The   intermediate then unfolds to form the yne diolate. The structures   of [U(C8H8)(C5H5)]C2O2, the deltate complex [U(C8H8)(C5H5)]C3O3   and the squarate complex [U(C8H8)(C5H5)]C4O4 are optimized and   provide good models for the experimental compounds. The reaction   of further CO with a zig-zag intermediate to form deltate and   squarate complexes was explored using Th(C8H8)(C5H5) as a model   and low energy pathways are proposed.

      Address (URL): http://pubs.rsc.org/en/content/articlehtml/2011/dt/c1dt10692a