Student Research Opportunities

Research in the Coym lab is focused on understanding the fundamental processes of reversed-phase, high performance liquid chromatography (RP-HPLC). RP-HPLC is the method of choice for the separation of non-volatile analytes. This technology is heavily employed in the pharmaceutical industry, in environmental analysis, in forensics, and in biochemical analysis (proteomics/metabolomics). Although RPLC is known to work well for the separation of non-volatile analytes, the mechanism responsible for retention and separation in RP-HPLC is still the subject of debate.

We investigate intermolecular processes that occur in the separation column. These include examination of retention mechanism—is retention by adsorption, partitioning, or a combination of these? What types of interactions occur between a solute, the stationary phase, and the mobile phase? How does changing experimental variables, such as temperature, stationary phase type, or mobile phase type, affect solute retention or separation selectivity? We employ van’t Hoff analysis to elucidate the thermodynamics of the retention process, as well as linear solvation energy relationships to examine the types of intermolecular interactions occurring when a solute is retained.

Design, synthesis, and evaluation of new ionic liquids is the principal focus of our work (supported largely by Chevron). Our efforts to create new ionic liquids fall into three overarching categories.

The first is in the area of “task-specific” ionic liquids (TSILs), a subgroup of ionic liquids first described by us in 1999 and first referred to as TSILs in 2000. TSIL – type ionic liquids may be distinguished from more “conventional” ionic liquids in that the anion, cation or both of the salt contains within its structure a “functional group” which (by design) imbues the salt with a specific chemical attribute.

The second general area of ionic liquids development by our group concerns the identification of recognizably non-toxic ions for evaluation in the formulation of ionic liquids. While the overwhelming focus of most IL research worldwide has to date centered on their eventual use as industrial solvents, we believe that appropriately non-toxic ionic liquids are tremendously promising materials for use in consumer products. By in large, our energies in this effort have been focused on the identification of anions which might be suitable for IL formulation but which do not contain fluorine, a common component of most IL-anions.

Most recently our attention has turned to examining the use of a long-neglected boron-centered cation type – the “boronium ion” –in creating new ionic liquids.

My research program lies primarily in the area of synthetic organic chemistry. A large component is dedicated toward the development of new methods involving the stereoselective construction of medicinally important compounds. The success of the program is heavily dependent upon the involvement of motivated and talented undergraduate students. Our research activities are in the area of asymmetric catalysis and synthetic methodology. There is a heavy emphasis toward the development of new methods in the stereoselective synthesis of organic compounds. In terms of the significance and importance of our research efforts, each project's long-term goal is toward the production of chiral molecules of high biological and medicinal importance. Our research program is a blend of both applied and basic research. The capstone experience is focused on chirality.

Synthesis and characterization of new ionic liquids for use as solvents and catalysts is the focus of our work. Our work covers both basic research and applications.

The first area is basic research. We are exploring the fundamental nature of ionic liquids and the question of what makes an ionic liquid a liquid? This research involves the synthesis of various ionic liquids, then analyzing the interactions between the cation and anion that lead to their unique properties. In our group, the analysis of the interaction is performed through thermal characterization by differential scanning calorimetry, thermal gravimetric analysis, crystallographic analysis (when the ILS are crystalline), variable temperature Raman spectroscopy (with collaborators at U.S. Naval Academy), and computational methods. These techniques combined provide an understanding of the complex interaction that produces an ionic liquid with a lower melting point.

The applications section of our research focuses on converting biopolymers, such as cellulose and chitin, into feedstock chemicals to replace petroleum based feedstocks. Ionic liquids have proven to be excellent solvents for the dissolution of various biopolymers, such as silk, cellulose, and chitin to name a few. Once dissolved the polymer chains are now more reactive to various chemical reactions. Our goal is to develop an IL acid catalyst that can depolymerize the biomass to its monomer unit, either glucose for cellulose or N-acetyl-D-glucosamine for chitin. This project involves the synthesis of new IL based acid catalysts utilizing several different reaction paths, some new, and characterizing the catalysts by simple organic reaction and by depolymerization of the biomass. This work is currently supported by the U.S. Air Force Office of Scientific Research.

More information coming soon.

Characterization of unknown compounds from extremely complex mixtures remains one of the major challenges in modern analytical chemistry. Complex mixtures in themselves are not necessarily crippling if enough is known about the components allowing for the design of highly specific separation techniques (this is generally taken advantage of for biological samples). True unknowns are somewhat more difficult, but can generally be structurally identified as long as enough information-rich data are compiled (e.g. NMR, IR, X-ray crystallography and mass spectra). The combination of complexity and true unknowns is, however, still a large stumbling block.

Mixtures too complex to be fractionated into individual components are relatively common in nature. Humic substances (the condensation and degradation products of dead and decaying plant and animal matter) are one such example. Humics are ubiquitous in nature and of great agricultural and environmental importance. More recently biomedical uses for these compounds (particularly as antiviral agents) have also been identified.

In this research group we are using chromatography and mass spectrometry to characterize humic substances on the molecular level. Research goals involve the development of pre-fractionation methods that reduce the overall complexity of humic mixtures; identification of structural components for individual humic molecules through tandem MS techniques; and mimicking of humic substances through synthetic standards.

My main area of research is in synthetic inorganic chemistry. My particular interests in this field are in the areas of structural chemistry of f-element compounds. There are two main groups of f-elements, the lanthanides and the actinides. All of the actinides are radioactive and many of them are quite rare, therefore it is quite challenging to conduct research using these elements. On the contrary, all of the lanthanide elements (except Pm) have stable isotopes and are relatively plentiful in nature. For these reasons we work primarily on studies involving the lanthanide elements, although we presently also have the licensing and capabilities to work with one actinide, Uranium.

One active area of research in my lab is the construction of functional f-element coordination polymers. A common impediment in lanthanide ion systems is that direct absorption of the f−f excited states is very inefficient. However, light harvesting ligands can be used to enhance the emission from the metal cation site. Ligands used for such applications usually have strong absorbance in the UV or visible regions and transfer their excited energy to the acceptor species (Ln cation). Chromophoric ligands that photosensitize lanthanide ion luminescence are of intense current interest. Such complexes are used in technological applications such as fluoroimmunoassays, cellular imaging, chemosensors, optical communications, and optoelectronic devices. A number of compounds have been studied that illustrate photosensitization of various f-elements. One of our main research aims is to prepare compounds that contain multiple donor groups for lanthanide sensitization.

Our primary scientific interests are focused on various aspects of structural chemistry. These in particular involve development of new quantum chemistry models to analyze infrared and microwave spectra of molecules performing large amplitude motions and theoretical and experimental studies in atomic and molecular spectroscopy. We utilize ab initio and Density Functional Theory approaches for determination of electronic, structural, and vibrational characteristics of organic, inorganic and organometallic compounds. Our scientific interests also include the application of quantum chemistry and molecular mechanics/dynamics to large macromolecular systems. In particular we are interested in structural aspects of enzyme inhibition.

Independently we are pursuing research in the area of surface science chemistry. Using both theoretical and experimental approaches, we are investigating structural and energetic aspects of adsorbate/surface interactions. On the theoretical side of this project, we are developing and applying new quantum chemistry models for the description of adsorption/desorption of atoms, small molecules, and macromolecules on crystal surfaces. We are using various experimental techniques, including crystal growth, polarized light microscopy and cryomicroscopy, scanning electron microscopy, single crystal x-ray crystallography and atomic force microscopy, to elucidate the adsorbate-crystal interactions that lead to control over crystal growth. These adsorbate-crystal interaction investigations involve, in particular, interactions between antifreeze proteins and ice crystals, polypeptide interactions with inorganic surfaces, design of inhibitors of kidney stones and inhibitors of arthritic degenerative calcification of joints in humans. Our interest in materials science also involves biomimetics and properties of magnetic materials with the emphasis on magnetic thin films.

Our group is interested in the synthesis and structure-activity relationships (SAR) of biologically active heterocyclic natural products in the anticancer area. Our research involves the state of the art development of transition metal-catalyzed reactions which significantly shortens a chemical synthetic route compared to classical organic chemistry schemes. We are interested in the development of ligands for metal-catalyzed cross-coupling and C-H activation reactions as a proof of principle methodology and then we apply these new reactions to selected heterocyclic biological targets. We use the techniques of organic chemistry to prepare biologically active compounds which we submit for assays, and then we use our skills as a medicinal chemist to synthesize more potent analogs of the compounds based on the available data obtained from the assays. Our group is exposed to how we can do “real world” research in an academic environment.