Photo of Geoff ClokeGeoff Cloke
Emeritus Professor (Chemistry)

Research

Research Group Website:

http://www.sussex.ac.uk/lifesci/clokelab/

Our main interests lie in the field of synthetic organometallic and co-ordination chemistry of the transition metals and f-elements, in particular: (i) the synthesis, via both conventional and metal vapour techniques, and reactivity of molecules which contain elements in unusual/unprecedented oxidation states, and which challenge the accepted limits of chemical bonding; understanding of the bonding in such molecules at the molecular level: P. L. Arnold, F. G. N. Cloke, P. B. Hitchcock and J. F. Nixon, 'The First Example of a Scandium(I) Complex: Synthesis and Molecular Structure of a 22-Electron Scandium Tripledecker Incorporating the Novel 1,3,5-Triphosphabenzene Ring', J.Am.Chem.Soc., 1996, 118, 7630 (ii) the development of new ligand environments for early transition metal and f-element organometallic complexes in conventional oxidation states; the synthesis of well-defined compounds relevant to stereo-controlled polymerisation and co-polymerisation of simple and polar olefins: F. G. N. Cloke, B. R. Elvidge, P. B. Hitchcock, and V. M. E. Lamarche, 'Yttrium iodide and bis(trimethylsilyl)methyl complexes of the chelating diamide [ArN(CH2)3NAr] (Ar= 2,6-iPr2C6H3)', J.Chem. Soc., DaltonTtrans., 2002, 2413. (iii) synthesis and reactivity of to two-coordinate, homoleptic Group 10 complexes of N-heterocyclic carbenes; applications to catalytic C-N and C-X bond forming reactions: A. K. de K. Lewis, S. Caddick, F. G. N. Cloke, N. C. Billingham, P. B. Hitchcock, and J. Leonard, 'Synthetic, Structural and Mechanistic Studies on the Amination of Aromatic Chlorides using Discrete Palladium (N-Heterocyclic -Carbene) Complexes', J. Am. Chem. Soc., 2003, 125, 10066; O. Esposito,  A. K. de K. Lewis,  P. B. Hitchcock,  S. Caddick, and F. G. N. Cloke, "Synthesis and reactivity of alkyl palladium N-heterocyclic carbene complexes" Chem. Commun, 2007, 1157; Alkylpalladium N-Heterocyclic Carbene Complexes: Synthesis, Reactivity, and Catalytic Properties, O. Esposito, P, M. P. Gois, A. K. de K. Lewis, S. Caddick, F. G. N. Cloke and Peter B. Hitchcock. Organometallics, 2008, 27 (24), pp 6411-6418 (iv) activation and cleavage of dinitrogen by early transition and actinide complexes: F. G. N. Cloke and P. B. Hitchcock, 'Reversible Binding and Reduction of Dinitrogen by a Uranium(III) Pentalene Complex', J. Am. Chem. Soc., 2002, 124, 9352 (v) early transition metal and f-element pentalene and related complexes; reductive cyclooligomerisation of CO and small molecule activation: O. T. Summerscalesa, F. G. N. Cloke, P. B. Hitchcock, J. C. Green, and N. Hazari, 'Reductive Cyclotrimerization of Carbon Monoxide to the Deltate Dianion by an Organometallic Uranium Complex, Science', 2006, 311, 829 Click for abstract  Click for full text  pdf reprint

A. S. Frey, F. G. N. Cloke, P. B. Hitchcock, I. J. Day, J. C. Green, and G. Aitken, "Mechanistic Studies on the Reductive Cyclooligomerisation of CO by U(III) Mixed Sandwich Complexes; the Molecular Structure of [(U(η-C8H6{SiiPr3-1,4}2)(η-Cp*)]2(μ-η1:η1-C2O2), J. Am. Chem. Soc., 2008, 130, 13816; A Dichromium(II) Bis(η8-pentalene) Double-Sandwich Complex with a Spin Equilibrium: Synthetic, Structural, Magnetic, and Theoretical Studies, G. Balazs, F. G. N. Cloke*, L. Gagliardi, J. C. Green, A. Harrison, P. B. Hitchcock, A. Rehaman Moughal Shahi, Owen T. Summerscales, Organometallics, 2008, 27 (9), pp 2013-2020;C. P. Larch, F. G.. N. Cloke. and P. B. Hitchcock, "Activation and reduction of diethyl ether by low valent uranium: formation of the trimetallic, mixed valence uranium oxo species [U(CpRR)(µ-I)2]3(µ3-O) (CpRR = C5Me5, C5Me4H, C5H4SiMe3)", Chem. Commun, 2008, 82 - 84; O. T. Summerscales, A. S. Frey, F.G.N. Cloke and P. B. Hitchcock "Reductive Disproportionation of Carbon Dioxide to Carbonate and Squarate Products Using A Mixed-Sandwich U(III) Complex", Chem. Commun., 2009,  198 - 200; A.S. P. Frey, F. G. N. Cloke, M. P. Coles, L. Maron, and T. Davin, “Facile Conversion of CO/H2 into Methoxide at a Uranium(III) Center”, Angew. Chem. Int. Ed. 2011, 50, 6881 –6883