Linking quantum chemistry and chemical reactivity

One of the cornerstones of rational chemical design is the ability to interpret the kinetics and thermodynamics of a chemical reaction in terms of the contributions of the substituents on the various reagents. In this way, one can study the properties of the substituents in one chemical process and use the information to predict how these substituents may behave in another chemical process. Unfortunately, there is no unambiguous method for the decomposition of reaction energies into contributions from substituent effects. Many different schemes exist for decomposing bond energies into intrinsic bond energies and intrinsic radical stabilities, and for decomposing electron densities within molecules into atomic charges and bond orders. However, as such intrinsic properties have no definition in quantum mechanics, there is no clear method for determining which schemes are most appropriate / accurate. Rather the success or failure of a method has to be judged in terms of its contribution to aiding our understanding and our ability to predict chemical behaviour. We are working toward converting these qualitative guidelines into more rigorous tests using intrinsic radical stabilities, and using then using these to evaluate energy and wavefunction decomposition schemes in a new light. Our ultimate aim is to improve our understanding of these difficult concepts, and develop better measures of intrinsic properties for use in structure-reactivity studies.

Selected Publications:

  • Coote, M.L., Lin, C.Y., & Zavitsas, A.A., (2014) Obtaining Inherent and Transferable Stabilization Energies of Carbon-centred and Heteroatom-centred Radicals on the Same Relative Scale and Their Applications, Phys. Chem. Chem. Phys, 16, pp. 8686–8696.
  • Lin, C.Y., Marque, S.R.A., Matyjaszewski, K., & Coote, M.L. (2011) Linear-Free Energy Relationships for Modeling Structure-Reactivity Trends in Controlled Radical Polymerization, Macromolecules, 44, pp. 7568–7583
  • Coote, M. L., Lin, C.Y., Beckwith, A.L.J. & Zavitsas, A.A. (2010) A Comparison of Methods for Measuring Relative Radical Stabilities of Carbon-Centred Radicals, Phys. Chem. Chem. Phys., 2010, 12,  9597-9610.
  • Coote, M. L. & Dickerson, A. B. (2008) The Measurement and Meaning of Intrinsic Radical Stability: Are Chemical Questions just Problems in Applied Mathematics? Aust J. Chem. 61,pp. 163–167


This project developed out of an ARC-funded study on intrinsic radical stability with Professor Andreas Zavitsas, Long Island University and the late great Professor Athel Beckwith, with philosophical input from Dr Adam Dickerson, University of Canberra. Our ongoing work on valence bond theory involves a collaboration with Professor Dan Ess, Brigham Young University, and Professor Sason Shaik, Hebrew University of Jerusalem. We applied some our findings to the development of an effective linear free energy relationship for controlled radical polymerization in collaboration with Professor Kris Matyjaszewski, Carnegie-Mellon, and Professor Sylvain Marque, Marseilles. A former group member, Dr Ching Yeh Lin, now at the NCI National Facility, played a key role in the original studies.