Dr Mark A. Fox
(email at firstname.lastname@example.org)
Our primary area of interest is the chemistry of carboranes. Carboranes are clusters containing boron and carbon atoms with terminal or bridging hydrogens. We are principally interested in the fundamental synthetic, chemical and physical properties of these compounds. They are characterised by spectroscopic (NMR, IR, UV-vis, MS, Raman), computational (DFT) and diffraction (X-ray) methods available from the excellent departmental research facilities here.
Clusters with unusual electron counts2
Geometries of carboranes tend to be either open or closed cages depending on the general skeletal electron counting rules pioneered by Prof Wade of this department. Generally, the closed cage geometries contain 2n+2 skeletal electrons (n = number of vertices) whereas the open cage geometries have 2n+4 skeletal electrons. We have determined a geometry containing 2n+3 skeletal electrons by a combination of spectroscopic and computational methods on a carborane anion radical.
Perhalogenation of clusters3
Replacing the hydrogens surrounding a carborane with halogens can result in vastly different chemical, geometrical and physical properties. For example, a halogen in place of a hydrogen atom can make the carborane more stable or more reactive. The geometry of the cage can be greatly distorted by the steric bulk of the chlorine, bromine or iodine atoms. The strongest known acids are those containing the very robust halogenated monocarborane anions.
A recent development in nanovehicle research involves the use of carborane clusters as wheels. We have developed convenient syntheses of ethynylcarboranes which are ideally suited to parts of the nanocar concept with the use of the ethynyl rods as axles.
- M. A. Fox, "Polyhedral Carboranes", Comprehensive Organometallic Chemistry III, Elsevier, 2007, p.49.
- M. A. Fox, C. Nervi, A. Crivello and P.J. Low, Chem. Commun., 2007, 2372.
- M. A. Fox and A. K. Hughes, Coord. Chem. Rev., 2004, 248, 457.
- M. A. Fox, T.E. Baines, D. Albesa-Jové, J.A.K. Howard and P.J. Low, J. Organomet. Chem., 2006, 691, 3889.
Journal papers: academic
- Kahlert, J., Böhling, L., Brockhinke, A., Stammler, H.-G., Newmann, B., Rendina, L.M., Low, P.J., Weber, L. & Fox, M.A. (2015). Syntheses and Reductions of C-Dimesitylboryl-1,2-dicarba-closo-dodecaboranes. Dalton Transactions 44(21): 9766-9781.
- Kahlert,J., Stammler, H.-J. Neumann, B., Harder, R.A. , Weber, L. & Fox, M.A (2014). Crystal structures of the carborane dianions, [1,4-(PhCB10H10C)2C6H4]2- and [1,4-(PhCB10H10C)2C6F4]2-, and the stabilizing role of the para-phenylene unit on unusual 2n+3 SE clusters. Angewandte Chemie International Edition 53(14): 3702-3705.
- Harder, R.A., MacBride, J.A.H., Rivers, G.P., Yufit, D.S., Goeta, A.E., Howard, J.A.K., Wade, K. & Fox, M.A. (2014). Studies on bis(1’-ortho-carboranyl)benzenes and bis(1’-ortho-carboranyl)biphenyls. Tetrahedron 70(34): 5182-5189.
- Weber, L., Kahlert, J., Brockhinke, R., Böhling, L., Halama, J., Brockhinke, A., Stammler, H.-J., Neumann, B., Nervi, C., Harder, R.A. & Fox, M.A. (2013). C,C′-Bis(benzodiazaborolyl)dicarba-closo-dodecaboranes: Synthesis, structures, photophysics and electrochemistry. Dalton Transactions 42(30): 10982-10996.
- Weber, Lothar, Kahlert, Jan, Boehling, Lena, Brockhinke, Andreas, Stammler, Hans-Georg, Neumann, Beate, Harder, Rachel A., Low, Paul J. & Fox, Mark A. (2013). Electrochemical and spectroelectrochemical studies of C-benzodiazaborolyl-ortho-carboranes. Dalton Transactions 42(6): 2266-2281.
- Ioppolo, Joseph A., Bhadbhade, Mohan, Fox, Mark A. & Rendina, Louis M. (2013). Remarkable cage deboronation and rearrangement of a closo-1,12-dicarbadodecaborane to form a neutral nido-7,9-dicarbaundecaborane. Chemical Communications 49(32): 3312-3314.
- Armstrong, David R., Fox, Mark A. & Wade, Ken (2012). Carboranes as model hypercarbon systems; structural and bonding patterns in selected isoelectronic closo-borane and carborane systems; [BnHn](2-), [1-CBn-1Hn](-) and 1,n-C2Bn-2Hn (n=5, 6, 7, 10 or 12). Journal of Organometallic Chemistry 721: 130-136.