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Prof Helder Marques

Position: DST/NRF South African Research Chairs Initiative Professor of Bioinorganic Chemistry, and Chair of Inorganic Chemistry
BScHons, PhD (Witwatersrand), HDipEd(PG), FRSSAfr, MRSC, CChem, MSACI
Department: Chemistry
Phone: 011 717 6737
Room: 301

Professor Marques obtained his BScHons (1979) and Postgraduate Diploma in Education (1979) from the University of the Witwatersrand, Johannesburg (Wits), and taught physics, chemistry and mathematics at high school for five years before returning to read for his PhD in bioinorganic chemistry. After the award of the PhD in 1986 he did post-doctoral at the University of Texas at Arlington. His PhD and post-doctoral work, on aspects of the chemistry of the iron porphyrins and the cobalt corrinoids (vitamin B12), respectively, are still the principal areas of his research interests.  Other research interests include the use of computational chemistry methods in bioinorganic chemistry, and the design of novel ligands for biomedical applications.  He was elected a Fellow of the Royal Society of South Africa (2005), is the recipient of the Vice Chancellor's Research Award (1989) and the Vice Chancellor's Teaching Award (1992) of this University, and the Raikes Medal (1989) and Merck Medal (2006) of the South African Chemical Institute. He is currently holder of the DST/NRF Chair in Bioinorganic Chemistry, is Professor of Bioinorganic Chemistry, and Chair of Inorganic Chemistry.  He served 9 years as Head of the School of Chemistry and is Assistant Dean (Research) of the Faculty of Science at Wits.

Research Interests

Professor Marque's research focus is in bioinorganic chemistry, and in the application of computational chemistry methods to problems in the structure of bioinorganic complexes. He is currently working on model compounds for the haemoproteins, designed to help elucidate the nature of the metal-protein partnership which leads to the unique catalytic properties of metalloenzymes; on the chemistry of the cobalt corrinoids with particular emphasis on how Co(III) is labilised; on the structure of cobalt corrinoids in solution.


P.R. Varadwaj, I. Cukrowski and H.M. Marques, DFT-UX3LYP Studies on the Coordination Chemistry of Ni2+.  Part 1: Six Coordinate [Ni(NH3)n(H2O)6-n]2+ Complexes.  J. Phys. Chem. A., 112, 10657-10666, 2008.

H. A. Hassanin, L. Hannibal, D. W. Jacobsen, K. L. Brown, H. M. Marques and N.E. Brasch. NMR Spectroscopy and molecular modelling studies of nitrosylcobalamin: Further evidence that the deprotonated, base-off form is important for nitrosylcobalamin in solution.  Dalton Trans., 424-433, 2009.

A.S. de Sousa, S.A. Reisinger, M.A. Fernandes, C.B. Perry, P.R. Varadwaj and H.M. Marques. The structure of N,N’-bis(2-hydroxyethyl)ethane-1,2-diamine and its complexes with Zn(II) and Cd(II), Dalton Trans., 10208–10218, 2009

P.R. Varadwaj and H.M. Marques.  The physical chemistry of coordinated aqua-, ammine-, and mixed-ligand Co2+ complexes: DFT studies on the structure, energetics, and topological properties of the electron density, Phys. Chem. Chem. Phys., 12, 2126–2138, 2010.

P.R. Varadwaj and H. M. Marques.  The physical chemistry of [M(H2O)4(NO3)2] (M = Mn2+, Co2+, Ni2+, Cu2+, Zn2+) complexes: Computational studies of their structure, energetics and the topological properties of the electron density. Theor. Chem. Acc., 127, 711-725, 2010.

A.S. de Sousa, M.A. Fernandes, K. Padayachy and H.M. Marques.  Amino-Alcohol Ligands: Synthesis and Structure of N,N′-bis(2-hydroxycyclopentyl)ethane-1,2-diamine and its Salts, and an Assessment of its Fitness and that of Related Ligands for Complexing Metal Ions.  Inorg. Chem., 49, 8003–8011, 2010.

C.F. Zipp, M.A. Fernandes, H.M. Marques, J.P. Michael and C.B. Perry. Polymorphs of N-[2-(hydroxymethyl)phenyl]benzamide: structural characterization and analysis of molecule···molecule interactions by means of atom-atom potentials and DFT.  Crystal Growth and Design, 11, 1431-1436, 2011.

S.M. Chemaly, K.L. Brown, M.A. Fernandes, O.Q. Munro, C. Grimmer, and H.M. Marques. Probing the Nature of the Co(III) Ion in Corrins: The Structural and Electronic Properties of Dicyano- and Aquacyanocobyrinic Acid Heptamethyl Ester and a Dicyano- and Aquacyano-Stable Yellow Cobyrinic Acid Heptamethyl Ester.  Inorg. Chem., 50, 8700-8718, 2011.

S.M. Chemaly, M. Florczak, H. Dirr and H.M. Marques. Probing the Nature of the Co(III) Ion in Corrins: A Comparison of the Thermodynamics and Kinetics of the Ligand Substitution Reactions of Aquacyanocobyrinic Acid Heptamethyl Ester and Aquacyano-Stable Yellow Cobyrinic Acid Heptamethyl Ester. Inorg. Chem., 50, 8719-8727, 2011.

P.R. Varadwaj, A. Varadwaj, G.H. Peslherbe and H.M. Marques. A Conformational Analysis of 18-Azacrown-6 and its Bonding With Late First Transition Series Divalent Metals: Insight from DFT Combined with NPA and QTAIM Analyses.  J. Phys. Chem. A, 115, 13180-13190, 2011.