Frustrated Lewis pair and Combined Electrochemical–Frustrated Lewis Pair ChemistryeFLP

Since Prof Doug Stephan introduced the concept of “frustrated Lewis pairs” (FLPs) researchers have been exploring ways in which the unquenched reactivity arising from a suitable combination of Lewis acids and Lewis bases that are too sterically bulky to form classical Lewis adducts can be used to activate small molecules, e.g. H2. We are interested in synthesising novel Lewis acidic boranes, boreniums, and other main group Lewis acidic species that can activate H2 and other small molecules (e.g. CO and CO2) via FLP chemistry, to effect metal-free chemical catalytic transformations. In particular, through a collaboration with Dr Andrew Ashley (Imperial College), we have pioneered the development of “combined electrochemical–frustrated Lewis pair” catalysts. These are capable of activating H2 via their FLP chemical capacity, whilst also allow us to oxidise the Lewis acid hydride intermediates formed when H2 is cleaved heterolytically at lower voltages, with larger currents. The development of these eFLP electrocatlaysts as a viable replacement for precious (and expensive!) metal catalysts used in fuel cells, such as Pt, is a key aim of our research.

Selected publications in this area:eFLP2

  1. An Electrochemical Study of Frustrated Lewis Pairs: A Metal-free Route to Hydrogen Oxidation
    Elliot J. Lawrence, Vasily S. Oganesyan, David L. Hughes, Andrew E. Ashley, Gregory G. Wildgoose, 
    J. Am. Chem. Soc., 2014, 136, 6031-6036 .

  2. Metal–Free Dihydrogen Activation by a Borenium Cation: A Combined Electrochemical/Frustrated Lewis Pair Approach
    Elliot J. Lawrence, Thomas J. Herrington, Andrew E. Ashley, Gregory G. Wildgoose,
    Angew. Chem. Int. Ed., 2014, 53, 9922-9925.

  3. A combined "electrochemical-frustrated Lewis pair" approach to hydrogen activation: surface catalytic effects at platinum electrodes
    Elliot J. Lawrence, Robin J. Blagg, David L. Hughes, Andrew E. Ashley, Gregory G. Wildgoose,
    Chem. Eur. J., 2014, DOI: 10.1002/chem.201404242.

  4. Separating electrophilicity and lewis acidity: the synthesis, characterisation and electrochemistry of electron deficient tris(aryl)boranes B(C6F5)3-n(C6Cl5)n (n=1-3)
    Andrew E. Ashley, Thomas J. Herrington, Gregory G. Wildgoose, Hasna Zaher, Amber L. Thompson, Nicholas H. Rees, Tobias Kraemer, Dermot O’Hare,
    J. Am. Chem. Soc., 2011, 133, 14727-14740

  5. Exploring the fate of the tris(pentafluorophenyl)borane radical anion in weakly coordinating solvents
    Elliot J. Lawrence, Vasily S. Oganesyan, Gregory G. Wildgoose and Andrew E. Ashley, 
    Dalton Trans., 2013, 42, 782–789.