Dr. Eric Bushnell
Physical chemistry, Computational/Theoretical chemistry, Biomimetic catalyst design.
Computational chemistry uses computers to model the chemistry of chemical systems that may be too difficult to study experimentally or to provide insight into observed phenomena that cannot be answered with current experimental methods. In particular, our research group uses computational/theoretical chemistry methods to investigate the chemistry of dithiolene- and diselenolene-metal complexes. A brief overview of dithiolene- and diselenolene-metal complexes is described below.
Since the 1960s dithiolene complexes have been intensely studied due to their rich and diverse chemistry. Notably, dithiolene-metal complexes have been investigated for potential use in the partitioning of spent nuclear fuels,1 the purification of olefins used in the production of polymers,2 dye-sensitized solar cells,3-4 and catalysts for the splitting of H2O to produce H25. In addition, such complexes have been investigated for use in magnetic materials,6-7 chemical microsensors8 and in optical limiting devices.8 More recently, Ni-bisdithiolene complexes have been investigated for use as photothermal therapeutic agents for the treatment of cancer.9
What leads to the unique chemistry of dithiolene- and diselenolene-metal complexes is that the ligands that contain the dithiolene/diselenolene functional group, which consists of an alkene and two thiols/selenols in a cis-configuration, are in fact prototypical redox-noninnocent ligands. Redox-noninnocent ligands not only impart unique electronic properties to the complexes they form but also strongly modify their catalytic activity.10 For instance, the incorporation of such ligands into base metal complexes results in reactivities normally reserved for noble metal complexes.10-12 Moreover, such ligands provide sites of reactivity distant from the metal providing greater rates of catalysis.11, 13
It has been stated that continued research into the chemistry of d-transition-metal complexes bound to redox-noninnocent ligands is of great importance.10 The identification of new noninnocent ligands that undergo redox chemistry will allow for the design of new catalysts to solve many contemporary problems.11 It has been estimated that more than 90% of the chemicals and pharmaceuticals manufactured by the US requires the use of catalysts.14
With the depletion of fossil fuels the design of new compounds that can convert solar energy into electrical or chemical energy is essential. Furthermore, from the continued burning of fossil fuels the production of CO2 continues, thus new compounds to sequester this green house gas is crucial. Importantly, the knowledge gained from this research program will provide new understanding into the chemistry of diselenolene complexes resulting in the design of new components for use in dye-sensitized solar cells, catalysts for the renewable production of H2 via the photocatalytic splitting of water and the reduction of CO2 to formate as an economical alternative to storing H2.
- Meskaldji, S.; Belkhiri, L.; Arliguie, T. r. s.; Fourmigué, M.; Ephritikhine, M.; Boucekkine, A., Inorg. Chem. 2010, 49 (7), 3192. doi: 10.1021/ic902135t.; 2. Li, H.; Brothers, E. N.; Hall, M. B., Inorg. Chem. 2014, 53 (18), 9679. doi: 10.1021/ic5011538.; 3. Moorcraft, L. P.; Morandeira, A.; Durrant, J. R.; Jennings, J. R.; Peter, L. M.; Parsons, S.; Turner, A.; Yellowlees, L. J.; Robertson, N., Dalton Trans. 2008, (48), 6940.; 4. Geary, E. A. M.; Yellowlees, L. J.; Jack, L. A.; Oswald, I. D. H.; Parsons, S.; Hirata, N.; Durrant, J. R.; Robertson, N., Inorg. Chem. 2005, 44 (2), 242. doi: 10.1021/ic048799t.; 5. Downes, C. A.; Marinescu, S. C., J. Am. Chem. Soc. 2015. doi: 10.1021/jacs.5b07020.; 6. Kato, R., Chem. Rev. 2004, 104 (11), 5319. doi: 10.1021/cr030655t.; 7. Hoshino, N.; Yoshii, Y.; Aonuma, M.; Kubo, K.; Nakamura, T.; Akutagawa, T., Inorg. Chem. 2012, 51 (23), 12968. doi: 10.1021/ic302093b.; 8. Tan, W. L.; Ji, W.; Zuo, J. L.; Bai, J. F.; You, X. Z.; Lim, J. H.; Yang, S. S.; Hagan, D. J.; Van Stryland, E. W., Appl. Phys. B 2000, 70, 809. doi: 10.1007/s003400000209.; 9. Mebrouk, K.; Chotard, F.; Le Goff-Gaillard, C.; Arlot-Bonnemains, Y.; Fourmigue, M.; Camerel, F., Chem. Commun. 2015, 51 (25), 5268. doi: 10.1039/c4cc08231a.; 10. de Bellefeuille, D.; Orio, M.; Barra, A.-L.; Aukauloo, A.; Journaux, Y.; Philouze, C.; Ottenwaelder, X.; Thomas, F., Inorg. Chem. 2015, 54 (18), 9013. doi: 10.1021/acs.inorgchem.5b01285.; 11. Chirik, P. J., Inorg. Chem. 2011, 50 (20), 9737. doi: 10.1021/ic201881k.; 12. Yan, Y.; Keating, C.; Chandrasekaran, P.; Jayarathne, U.; Mague, J. T.; DeBeer, S.; Lancaster, K. M.; Sproules, S.; Rubtsov, I. V.; Donahue, J. P., Inorg. Chem. 2013, 52 (11), 6743. doi: 10.1021/ic4009174.; 13.Appel, A. M.; Bercaw, J. E.; Bocarsly, A. B.; Dobbek, H.; DuBois, D. L.; Dupuis, M.; Ferry, J. G.; Fujita, E.; Hille, R.; Kenis, P. J. A.; Kerfeld, C. A.; Morris, R. H.; Peden, C. H. F.; Portis, A. R.; Ragsdale, S. W.; Rauchfuss, T. B.; Reek, J. N. H.; Seefeldt, L. C.; Thauer, R. K.; Waldrop, G. L., Chem. Rev. 2013, 113 (8), 6621. doi: 10.1021/cr300463y.; 14. Bloksberg-Fireovid, R.; Hewes, J. In NIST (US National Institute of Standards and Technology) Advanced Technology Program Report, 1998.
- Bushnell, EAC. (2016). A Computational Investigation Into The Catalytic Activity Of A Diselenolene Sulfite Oxidase Biomimetic Complex, Canadian Journal of Chemistry (Invited to special issue in honor of Professors Russell Boyd and Arvi Rauk of Canada), DOI: 10.1139/cjc-2016-0244
- Forget SM, Bushnell EAC, Boyd RJ. Jakeman DL. (2016). The acidity of beta-phosphoglucomutase monofluoromethylenephosphonate ligands probed by NMR spectroscopy and quantum mechanical methods. Canadian Journal of Chemistry. 1-7
- Bushnell EAC, Boyd RJ. (2015). Identifying similarities and differences between analogous bisdithiolene and bisdiselenolene complexes: A computational study. International Journal of Quantum Chemistry. 116(5), 369-376
- Bushnell EAC, Boyd RJ. (2015). An assessment of several DFT functionals in the calculation of reduction potentials for Ni-, Pd- and Pt-bis-ethylene-1,2-dithiolene and diselenolene complexes. Journal of Physical Chemistry A. 119(5): 911-918.
- Adams MR*, Bushnell EAC, Grindley TB, Boyd RJ. (2014). Organotin bond dissociation energies: An interesting challenge for contemporary computational methods. Computational and Theoretical Chemistry. 1050: 7-14.
- MacDonald CA*, Bushnell EAC, Gauld JW, Boyd RJ. (2014). The catalytic formation of leukotriene C4: A critical step in inflammatory processes. Physical Chemistry Chemical Physics. 16(30): 16284-16289.
- Bushnell EAC, Burns TD*, Boyd RJ. (2014). The one-electron reduction of dithiolate and diselenolate ligands. Physical Chemistry Chemical Physics. 16(22): 10897-10902.
- Bushnell EAC, Burns TD*, Boyd RJ. (2014). The one-electron oxidation of a dithiolate molecule: The importance of chemical intuition. The Journal of Chemical Physics (Invited to special issue: Advances in Density Functional Theory Methodology). 140(18): 18A519.
- De Luna P*, Bushnell EAC, Gauld JW. (2013). A molecular dynamics examination on mutation-induced catalase activity in coral allene oxide synthase. Journal of Physical Chemistry B. 117(47): 14635-14641.
- Bushnell EAC, Gherib R*, Gauld J. (2013). Insights into the catalytic mechanism of allene oxide synthase: A dispersion corrected density functional theory study. Journal of Physical Chemistry B. 117(22): 6701-6720.
- De Luna P*, Bushnell EAC, Gauld JW. (2013). A density functional theory investigation into the binding of the antioxidants ergothioneine and ovothiol to copper. Journal of Physical Chemistry A. 117(19): 4057-4065.
- Bushnell EAC, Jamil R*, Gauld JW. (2013). Insights into the chemistry of lipoxygenases (LOXs): A computational investigation into the catalytic mechanism of 8R-LOX. Journal of Biological Inorganic Chemistry. 18(3): 343-355.
- Bushnell EAC, Gauld JW. (2013). An assessment of pure, hybrid, meta, and hybrid-meta GGA density functional theory methods for open-shell systems: The case of the nonheme ironenzyme 8R–LOX. Journal of Computational Chemistry. 34(2): 141-148.
- Bushnell EAC, Fortowski GB*, Gauld JW. (2012). Iron-oxo species and the oxidation of imidazole: Insights into the mechanism of OvoA and EgtB. Inorganic Chemistry. 51(24): 13351-13356.
- Bushnell EAC, Huang WJ, Llano J, Gauld JW. (2012). Molecular dynamics investigation into substrate binding and identity of the catalytic base in the mechanism of threonyl-tRNA synthetase. Journal of Physical Chemistry B. 116(17): 5205-5212.
- Huang WJ, Bushnell EAC, Francklyn CS, Gauld JW. (2011). The α-amino group of the threonine substrate as the general base during tRNA aminoacylation: A new version of substrate-assisted catalysis predicted by hybrid DFT. Journal of Physical Chemistry A (Invited to special issue: Richard F. W. Bader Festschrift). 115(45): 13050-13060.
- Ion BF, Bushnell EAC, De Luna P*, Gauld JW. (2011). An MD and QM/MM study on ornithine cyclodeaminase (OCD): A tale of two iminiums. International Journal of Molecular Sciences (Invited to special issue: Enzyme Optimization and Immobilization). 13(10): 12994-13011.
- Almasi JN*, Bushnell EAC, Gauld JW. (2011). A QM/MM–based computational investigation on the catalytic mechanism of saccharopine reductase. Molecules (Invited to special issue: Enzyme-Catalyzed Reactions). 16(10): 8569-8589.
- Bushnell EAC, Huang WJ, Gauld JW. (2011). Applications of potential energy surfaces in the study of enzymatic reactions. Advances in Physical Chemistry (Invited review article). 2012
- Bushnell EAC, Erdtman E, Llano J, Eriksson LA, Gauld JW. (2011). The first branching point in porphyrin biosynthesis: A systematic docking, molecular dynamics and quantum mechanical/molecular mechanical study of substrate binding and mechanism of uroporphyrinogen-III decarboxylase. Journal of Computational Chemistry. 32(5): 822-834.
- Erdtman E, Bushnell EAC, Gauld JW, Eriksson LA. (2011). Computational studies on Schiff-base formation: Implications for the catalytic mechanism of porphobilinogen synthase. Computational and Theoretical Chemistry. 963(2-3): 479-489.
- Erdtman E, Bushnell EAC, Gauld JW, Eriksson LA. (2010). Computational insights into the mechanism of porphobilinogen synthase. Journal of Physical Chemistry B. 114(50): 16860-16870.
- Bushnell EAC, Berryman VEJ, Gauld JW, Boyd RJ. (2015). The Importance of the MM Environment and the Selection of the QM Method in QM/MM Calculations: Applications to Enzymatic Reactions. Ed. Karabencheva-Christova T. Advances in Protein Chemistry and Structural Biology: Combined Quantum Mechanical and Molecular Mechanical Modelling of Biomolecular Interactions. : 1-28.
- Bushnell EAC, Llano J, Eriksson LA, Gauld JW. (2011). Mechanisms of Mutagenic DNA Nucleobase Damages and Their Chemical and Enzymatic Repairs Investigated by Quantum Chemical Methods. Ed. Chen CC. Selected Topics in DNA Repair. : 389-414.
Dr. Eric Bushnell, BSc, BSc, PhD (Associate Professor)
Department of Chemistry
Room 4-12, John R. Brodie Science Centre
270 18th Street
Brandon, Manitoba, Canada R7A 6A9
Phone: (204) 571-7899
Fax: (204) 728-7346