N.P. McKnight (Sadler) B.Sc. (Special), Ph.D., U.W.I. Lecturer (Inorganic) novelette.sadlermcknight@uwimona.edu.jm

Research Interests

1. Binuclear complexes as models for Molybdenum containing Enzymes. Complexes of molybdenum with amino-acids and sulfur containing ligands are of interest as possible models for molybdenum containing enzymes, e.g. xanthine oxidase and nitrogenase. It has been established that most of these enzymes contain two molybdenum atoms which are redox active. The molybdenum atoms are in oxidation state six in the oxidized form and in the reduced form may be as low as three. The di-μ-oxo species, Mo₂O₄(cys)₂^2- is one of the most widely studied chemical models for the molybdenum containing site of nitrogenase and its behavior mimics that of the enzyme in many respects. This project will involve the synthesis of similar complexes with a variety of ligands and the extent to which these complexes mimic the enzymes will be investigated. The reactivity of the complexes with a number of oxidizing and reducing agents as well as their electrochemical properties will be determined.

2. Inorganic Reaction Mechanisms. see T.P. Dasgupta for details.

3. Electron Transfer Reactions and electrochemistry of metal complexes.

4. Catalysis of hydrolysis of phosphate esters using transition metal comlexes.

Selected publications

• N.P. Sadler, C.C. Chung and R.M. Milburn, "Iron(III) Promoted Hydrolysis of 4-Nitrophenyl Phosphate" Inorganic Chemistry, 34, 402, 1995.

• N.P. Sadler, H. Jacobs, "Improved Spectrophotometric Assay for Salbutamol in Various Pharmaceutical Preparations", Talanta 42, 1385, 1995

• N.P. Sadler, D.A. Dixon, T.P. Dasgupta, "Oxidation of L-Ascorbic Acid by Pentaammineaquacobalt(III) Ion in Aqueous Solution", Transition Metal Chemistry, 20, 295, 1995.

• N.P. Sadler, D.A. Dixon, T.P. Dasgupta, "Mechanism of Oxidation of DL-Penicillamine and Glutathione by Chromium(VI) in Aqueous Solution", Journal of the Chemical Society, Dalton Transactions, 2267, 1995.

• N.P. Sadler, D.A. Dixon, T.P. Dasgupta, "Mechanism of Oxidation of L-ascorbic acid by the Pentaamminechromatocobalt(III) complex ion in Aqueous Solution", Journal of the Chemical Society, Dalton Transactions, 1903, 1997.