School of Humanities and Sciences
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Suman Patra
Postdoctoral Scholar, Chemistry
BioDr. Suman Patra is a postdoctoral researcher in the Department of Chemistry at Stanford University, working under the mentorship of Prof. Edward I. Solomon. His research focuses on uncovering the mechanistic intricacies of non-coupled binuclear copper (NBC) enzymes, particularly tyramine β-monooxygenase (TBM), which catalyzes oxygen activation and selective C–H bond hydroxylation.His work integrates high-resolution spectroscopy, transient kinetics, and protein biochemistry to probe the formation, structure, and reactivity of short-lived copper-oxygen intermediates. As part of this effort, he performs cell culture and protein purification, enabling the isolation of active, recombinant copper enzymes for detailed spectroscopic and mechanistic studies. Through a multi-spectroscopic approach, primarily UV-Vis, CD, MCD, EXAFS, EPR, resonance Raman, and stopped-flow absorption spectroscopy, he investigates how the geometric and electronic structure of the active sites modulate reactivity and enable O₂ activation without direct Cu–Cu coupling.
Dr. Patra earned his Ph.D. in Chemistry from the Indian Association for the Cultivation of Science (IACS), Kolkata, under the supervision of Prof. Abhishek Dey, where he developed iron porphyrin-based electrocatalysts for the selective reduction of CO₂. His research emphasized mechanistic analysis using electrochemical methods coupled with in situ spectro-electrochemistry to monitor redox transitions and catalytic intermediates under applied potentials. These studies were complemented by density functional theory (DFT) calculations, which he used to model key intermediates, protonation pathways, and redox energetics, thereby providing molecular-level insight into how second-sphere interactions and ligand environments influence catalytic behaviour. His integrative experimental–computational approach provided a detailed understanding of structure-function relationships in multi-electron CO₂ reduction.
The mechanistic perspective and technical skillset developed during his doctoral work, particularly in combining spectroscopy, electrochemistry, and computation, now form the foundation of his postdoctoral research. His current studies extend those same principles to more complex metalloenzyme systems, addressing similar core questions about the role of electronic structure, metal-ligand coordination, and local environment in controlling reactivity. His long-term goal is to bridge synthetic and biological catalysis through a mechanistic lens, contributing to the development of efficient, selective systems for small-molecule activation and sustainable energy transformations.
Dr. Patra received his M.Sc. in Chemistry from the Indian Institute of Technology (IIT) Guwahati after qualifying the national IIT-JAM examination and completed his B.Sc. in Chemistry at St. Xavier’s College, Kolkata. Over the course of his academic training, he has cultivated a multidisciplinary research identity that spans coordination chemistry, spectroscopy, electrochemical catalysis, and theoretical modelling. His scientific vision centres on using spectroscopic and computational insight to guide the rational design of catalysts for environmentally relevant redox chemistry. -
Robert Pecora
Professor of Chemistry, Emeritus
Current Research and Scholarly InterestsThe development of the basic principles behind the dynamic light scattering (DLS) technique and its application to a wide variety of liquid systems is one of Pecora's outstanding contributions to physical chemistry. DLS is now an indispensable tool in the repertoire of polymer, colloid and biophysical chemists. It is generally accepted to be one of the best methods for measuring the mutual diffusion coefficients and, in dilute systems, the hydrodynamic sizes of polymers and particulates in solution or suspension. It is widely used, among other things, for studying size distributions of polymer and colloid dispersions; for testing theories of polymer dynamics in dilute and concentrated systems; and for studying interactions between macromolecules and colloidal particles in liquid dispersions. The basic work that established the foundation of this technique was done in the 1960s. Pecora has revisited this area over the years-formulating theories, for instance, of scattering from hollow spheres, large cylindrically symmetric molecules and wormlike chains.
An experimental program began in the early seventies resulted in a now classic series of studies on the rotational dynamics of small molecules in liquids. This work, utilizing mainly depolarized DLS and carbon 13 nuclear magnetic relaxation, has had a wide impact in the area of liquid state dynamics.
It was also during this period that the theoretical foundation for the fluorescence correlation spectroscopy technique (FCS) was formulated. Because of recent advances in equipment and materials, this technique has recently been revived and is now a powerful tool in biophysics.
The experimental and theoretical techniques developed for the study of the dynamics of relatively simple small molecule liquids have been used to investigate more complex systems such as the rotation of small molecule solvents in glassy and amorphous polymers. The resonance- enhanced depolarized light scattering technique was also developed in this period.
Extensive studies using depolarized dynamic light scattering (using the Fabry-Perot interferometer) as well as photon correlation spectroscopy, NMR, FCS and small angle X-ray scattering to the dynamics of oligonucleotides have determined the hydrodynamic diameter of DNA and the internal bending angles of the bases. They also provided support for relations relating hydrodynamic parameters to molecular dimensions for short rodlike molecules and “polyelectrolyte effects” on the translational and rotational motions of these highly charged molecules.
A major area of experimental and theoretical study has been the study of the dynamics of rigid and semirigid rodlike polymers in both dilute and semidilute dispersions. The work on translation and rotation of poly (-benzyl-L-glutamate) in semidilute solution is a foremost early work in this area.
The Pecora group has synthesized and studied the dynamics of model
rigid rod/sphere composite liquids. Studies of the translation of dilute spheres through solutions of the rods as functions of the rod and sphere sizes and the rod concentrations have provided the stimulus for more experiment and theoretical work in this area. Transient electric birefringence decay studies of the rotation of dilute rigid rod polymers in suspensions of comparably sized spherical particles have revealed scaling laws for the rod rotation.
A unique feature of part of this work on rigid and semirigid rodlike polymers is the utilization of genetic engineering techniques to construct a monodisperse, homologous series of DNA restriction fragments. These biologically-produced fragments have served as well-characterized model macromolecules for solution studies of the dynamics of semirigid rodlike polymers.
The well-regarded book of Pecora and Berne on dynamic light scattering, first published in 1976, has become a major reference work. It is now a Dover paperback.
