""Assistant Professor
email
Center for Biophysical Sciences and Engineering 234A
(205) 996-1395

Research and Teaching Interests: Inorganic and Bioinorganic Chemistry, Inorganic Structure and Spectroscopy, Metalloenzymes – Structure and Function, Bio-inspired Model Chemistry, Environmentally Benign (Green) Catalysis, and Pathways to Careers in Chemistry

Office Hours: By appointment

Education:
  • B.Sc. (Chemistry with Honors), University of Colombo, Sri Lanka, 2009
  • Ph.D. (Inorganic Chemistry with Honors), University of Kansas, 2015

Dr. Gayan B. Wijeratne joined UAB in 2018, and is currently an Assistant Professor of Chemistry. He was born in Kandy, Sri Lanka, and received his B.Sc. (Honors) degree in chemistry from the University of Colombo, Sri Lanka, where his research on transition metal complexes of Sri Lankan natural products was recognized by the Professor R. S. Ramakrishna Memorial Gold Medal in inorganic chemistry in 2009.

Wijeratne Group is Actively Recruiting!

We are currently recruiting motivated undergraduate, graduate and postdoctoral researchers in our lab. If interested, please contact Dr. Wijeratne at wijeratne@uab.edu. We are excited to welcome you onboard!

He moved to the United States in 2010 and carried out his graduate research in the laboratory of Professor Timothy A. Jackson at the University of Kansas, working on bioinspired manganese complexes that bind dioxygen and its reduced derivatives, as well as on thermodynamic and kinetic studies of proton-coupled electron transfer reactivity of manganese-based oxidants. There he won the Higuchi Doctoral Progress Award in 2015, the highest graduate distinction at the University of Kansas. He carried out his postdoctoral research in the laboratory of Professor Kenneth D. Karlin at Johns Hopkins University from 2015 to 2018, where his research interests were focused on understanding heme and/or copper interactions with nitrogen oxides, primarily the mechanistic aspects involved with the reductive coupling of nitric oxide to nitrous oxide. He was also involved in dioxygen reduction and substrate oxidation reactivity studies of heme/copper assemblies.

Dr. Wijeratne’s research program at UAB is geared toward interrogating key mechanistic details pertaining to various crucial biologically and/or industrially relevant inorganic processes utilizing small-molecule, synthetic model compounds. This research interface between synthetic inorganic/organic chemistry, structural, spectroscopic, and theoretical characterization methodologies, and detailed thermodynamic and kinetic investigations of reactivity patterns. This research program is designed to produce all-rounded researchers with multidisciplinary chemical proficiencies, that range from traditional fundamental topics to state-of-the-art inorganic chemistry applications. The ultimate goal is aimed at comprehending the implications and significance of inorganic transformations/mechanisms of interest in human health and therapeutics, future sustainable catalysis, and next generation alternative energy applications.

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Nature has evolutionarily integrated metal centers in some of its most crucial/efficient functional proteins, most of which successfully mediate catalytic chemical transformations under entirely environmentally benign, ambient conditions. The pivotal nature of these metalloenzyme biochemistries often implicate them in human disease and diagnostics, whereupon a clear comprehension of their mechanistic details may lead to effective therapeutics against some of the most challenging pathological conditions humans face in present day, such as cancer, Alzheimer’s or Huntington’s. The efficiency in which nature utilizes these greener, cheaper metal systems in enzymatic catalytic turnovers also offers invaluable chemistry lessons to humans on how to move away from toxic, expensive catalytic metals that are currently in use for industrial-scale bulk transformations.

Wijeratne Research Laboratory utilizes synthetic organic and inorganic chemical tools to generate inorganic model complexes that resemble metalloprotein active sites, and then studies their reactivity profiles with small molecule biological substrates such as dioxygen (O2) and/or nitrogen oxides (NOx’s; e.g., NO, N2O, NO¬2–, NO3–) under inert laboratory conditions (i.e., utilizing glovebox/Schlenk techniques). One of the primary goals of this work is to identify biologically relevant intermediates/active species using synthetic model systems. Such reaction intermediates often display impaired thermal/chemical stability, and thus require specialized low-temperature techniques for unequivocal characterization. An array of separation, purification, and spectroscopic and structural characterization strategies will be applied, such as chromatography, electronic absorption (UV-Vis), electronic paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), Infrared (IR), resonance Raman (rR), and X-ray absorption (XANES & EXAFS) spectroscopies, mass spectrometry, and X-ray diffraction (XRD) along with electrochemical analysis (e.g., cyclic voltammetry (CV)). Careful thermodynamic and kinetic analyses (i.e., Eyring-, Arrhenius-, Polanyi-, and Hamett-type, kinetic isotope effects (KIE), and bond dissociation (free) energy (BD(F)E) calculations) of substrate and/or self reactivities of these species will lead into crucial insights that relate to key unknowns pertaining to the corresponding metalloprotein systems. Complementary Density Functional Theory (DFT) computations will also be employed as warranted. Comprehensive understanding of the bio-related chemistry will pave the way into novel, more effective therapeutics, as well as greener (nature-inspired) methodologies for industrial scale catalytic applications. The undergraduate, graduate and postdoctoral researchers engaged in these research attempts will progress to adepts in synthetic, spectroscopic and structural approaches for tackling mechanistic ambiguities, with sound knowledge of biological, inorganic, organic and physical chemistries, and their potential roles in industrial applications. Wijeratne Research Group actively collaborates with multiple on-campus, local and international research groups and national labs/facilities, including the UAB Center for Free Radical Biology (CFRB).

Dr. Wijeratne is also the organizer of a seminar series themed “Pathways to Chemistry Careers”, which strives to provide a broader perspective on career opportunities that are available for future chemistry graduates. Both academic and industrial professionals will be invited on-campus for seminars/discussions.
  • CH 345. Inorganic Chemistry: Principles and Applications in Chemical Periodicity
  • CH 345L. Inorganic Chemistry Lab: Principles and Applications in Chemical Periodicity
  • Suzanne M. Adam, Gayan B. Wijeratne, Patrick J. Rogler, Daniel E. Diaz, David A. Quist, Jeffrey J. Liu, and Kenneth D. Karlin Synthetic Fe/Cu Complexes: Toward Understanding Heme-Copper Oxidase Structure and Function. Chem. Rev., 2018, Accepted Manuscript submitted for an invited review article to be published in the 2018 special issue titled “Oxygen Reduction and Activation in Catalysis”.
  • Gayan B. Wijeratne, Melissa C. Denler, Derek B. Rice, Hannah E. Colmer, Victor W. Day, and Timothy A. Jackson MnIII-Peroxo Adduct Supported by a New Tetradentate Ligand Shows Acid-Sensitive Aldehyde Deformylation Reactivity. Dalton Trans., 2018, Advanced Article.
  • Joshua D. Parham, Gayan B. Wijeratne, Derek B. Rice, and Timothy A. Jackson Spectroscopic and Structural Characterization of Mn(III)–alkylperoxo Complexes Supported by Pentadentate Amide-containing Ligands. Inorg. Chem., 2018, 57, 2489–2502.
  • Derek B. Rice, Gayan B. Wijeratne, and Timothy A. Jackson Mn K-edge X-ray Absorption Studies of Mononuclear Mn(III)–hydroxo Complexes. J. Biol. Inorg. Chem. 2017, 22, 1281–1293.
  • Gayan B. Wijeratne, Shabnam Hematian, Maxime A. Siegler, and Kenneth D. Karlin Copper(I)/NO(g) Reductive Coupling Producing a trans-Hyponitrite Bridged Dicopper(II) Complex – Redox Reversal giving Copper(I)/NO(g) Disproportionation. J. Am. Chem. Soc. 2017, 139, 13276–13279.
  • Derek B. Rice, Gayan B. Wijeratne, Andrew D. Burr, Joshua D. Parham, Victor W. Day, and Timothy A. Jackson Steric and Electronic Influence on Proton-coupled Electron-transfer Reactivity of a mononuclear Mn(III)-hydroxo Complex. Inorg. Chem. 2016, 55, 8110–8120.
  • Gayan B. Wijeratne, Eva M. Zolnhofer, Skye Fortier, Lauren N. Grant, Patrick J. Carroll, Chun-Hsing Chen, Karsten Meyer, J. Krzystek, Andrew Ozarowski, Timothy A. Jackson, Daniel J. Mindiola, and Joshua Telser Electronic Structure and Reactivity of a Well-defined Mononuclear Complex of Ti(II) Inorg. Chem. 2015, 54, 10380–10397.
  • Gayan B. Wijeratne, Victor W. Day, and Timothy A. Jackson O–H Bond Oxidation by a Monomeric Mn(III)–OMe Complex Dalton Trans. 2015, 44, 3295–3306.
  • Gayan B. Wijeratne, Briana Corzine, Victor W. Day, and Timothy A. Jackson Saturation Kinetics in Phenolic O–H Bond Oxidation by a Mononuclear Mn(III)–OH Complex Derived from Dioxygen Inorg. Chem. 2014, 53, 7622–7634.
  • Member, American Association for the Advancement of Science – 2018 to present
  • Member, American Chemical Society – 2011 to present
  • Member, Sri Lanka Association for the Advancement of Science – 2009 to present
  • Doctoral Dissertation Honors, University of Kansas – 2015
  • The Higuchi Doctoral Progress Award for the most outstanding graduate student, University of Kansas – 2015
  • Amini/Bailey Scholarship for research excellence, University of Kansas – 2014
  • Emily V. Berger Scholarship outstanding incoming graduate student, University of Kansas – 2010
  • R. S. Ramakrishna Memorial Gold Medal in Inorganic Chemistry for undergraduate research accomplishments, University of Colombo, Sri Lanka – 2009
  • Acting Principle Investigator, Johns Hopkins University – 2018
  • Mentored research projects of two graduate student researchers, Johns Hopkins University – 2015 to 2018
  • Postdoctoral Research Associate, Johns Hopkins University – 2015 to 2018
  • Mentored research projects of two undergraduate (for NSF-REU program in 2013) and two graduate student researchers, University of Kansas – 2013 to 2015
  • X-ray Absorption Team Leader, Brookhaven National Laboratory – 2014 to 2015
  • Graduate Research Assistant, University of Kansas – 2010 to 2015
  • Graduate Teaching Assistant, University of Kansas – 2010 to 2013
  • Undergraduate Teaching/Laboratory Assistant, University of Colombo, Sri Lanka – 2009 to 2010
  • Undergraduate Research Assistant, University of Colombo, Sri Lanka – 2007 to 2009