Dr. Ian Riddlestone
Synthetic Inorganic Chemistry
Junior Fellow (Alexander von Humboldt Fellow)
September 2016 - August 2017
Ian obtained his MChem degree at Newcastle University in the UK graduating in 2009. As a Masters student Ian worked in the group of Dr. Keith Izod investigating the light-induced rearrangement of thioether-substituted phosphanide ligands. Ian then moved to the University of Oxford where he was a BP CASE Award student working in the group of Prof. Simon Aldridge. As a DPhil student Ian worked on the formation of mixed transition metal-aluminium complexes. This work included the isolation and full characterisation of sigma-alane complexes comparable with archetypal dihydrogen, borane and silane complexes allowing fundamental bonding descriptions to be further developed for group 13 sigma complexes.
After obtaining a DPhil in Inorganic Chemistry in 2013 Ian moved to the University of Bath to take up an EPSRC funded postdoctoral position in the group of Prof. Michael Whittlesey. During this time Ian worked on the synthesis and reactivity of ruthenium carbene complexes, with particular emphasis on the activation of C-F bonds. In collaboration with the group of Prof. Stuart Macgregor (Heriot Watt University) this work highlighted the subtleties of supporting N-heterocyclic carbene ligands in ruthenium hydride chemistry. These differences impact upon product distributions in catalytic hydrodefluorination reactions of perfluorinated substrates, as well as the competition between C-F and C-H bond activation processes.
- σ-Alane Complexes of Chromium, Tungsten and Manganese. I.M. Riddlestone, S. Edmonds, P. Kaufman, J. Urbano, J.I. Bates, M.J. Kelly, A.L. Thompson, R. Taylor and S. Aldridge, J. Am Chem. Soc., 2012, 134, 2551. DOI: 10.1021/ja21198921.
- Coordination and Activation of Al-H and Ga-H Bonds. J.A.B. Abdalla, I.M. Riddlestone, J.Turner, P.A. Kaufman, R. Tirfoin, N. Phillips and S. Aldridge, Chem. Eur. J., 2014, 20, 17624. DOI: 10.1002/chem.201405018.
- Mechanistic Study of Ru-NHC-Catalyzed Hydrodefluorination of Fluoropyridines: The Influence of the NHC on the Regioselectivity of C–F Activation and Chemoselectivity of C–F versus C–H Bond Cleavage. D. McKay, I.M. Riddlestone, S.A. Macgregor, M.F. Mahon and M.K. Whittlesey, ACS Catal., 2015, 5, 776. DOI: 10.1021/cs501644r.
- Cooperative bond activation and catalytic reduction of carbon dioxide at a Group 13 metal center. J.A.B. Abdalla, I.M. Riddlestone, R. Tirfoin and S. Aldridge, Angew. Chem. Int. Ed., 2015, 54, 5098. DOI: 10.1002/anie.201500570.
- Isolation of [Ru(IPr)2COH]+ (IPr = 1,3-Bis(2,6-diidopropylphenyl)imidazol-2-ylidene) and Reactivity Toward E-H (E = H, B) Bonds. I.M. Riddlestone, D. McKay, M.J. Gutmann, S.A. Macgregor, M.F. Mahon, H.A. Sparkes and M.K. Whittlesey, Organomet., 2016, 35, 1301. DOI:10.1021/acs.organomet.6b00173
Preparation of Stabilised and Free Silylium and Silicocenium Ions Featuring Known and Novel Weakly Coordinating Anions; Reagents for the Coordination and Activation of Small Molecules
Weakly coordinating anions (WCAs) have applications as electrolytes, components in ionic liquids, lithium ion batteries and in catalysis. They also facilitate the formation of reactive cations and weakly bound complexes in the condensed phase. Although a number of WCAs are prevalent in the literature, a number of common underlying deficiencies affect their usage. Such deficiencies include: (i) stability to highly Lewis acidic species, (ii) weak coordinative strength, (iii) ease of preparation and (iv) high tendency towards crystallographic disorder. This project seeks to build and improve upon the perfluoro-tert-butoxy aluminate class of WCAs and apply these anions in the synthesis of highly reactive silylium and silicocenium cations.