Molecular Recognition (MS8105).

This is a graduate course in the Master of Science in Molecular Science.

For more information see

www.ryerson.ca/graduate/programs/molecular_science/
Chemistry of Photographic Deterioration (PP8105).

This is a graduate course in the Master of Arts, Photographic Preservation and Collections Management.
For more information see

www.imagearts.ryerson.ca/photopreservation/

My research explores the nature and uses of host-guest complexes. It can be divided into three thematic areas.


Theme 1: This deals with binding of model and real drug compounds (D) to cyclodextrins (CDs). The aim is to develop strategies for improved drug stability. Current efforts are focussed on exploring novel encapsulation systems consisting of higher-order drug-CD complexes. Encapsulated drugs should be less prone to degradation by ambient reagents, that is, rate constant kC < kF. An informative model for such complexes is the naphthalene:beta-CD system. Under some conditions this system spontaneously forms complexes of 2 CD molecules and 2 naphthalene molecules. This should strongly encapsulate the naphthalene and thus isolated it the surrounding environment. The system is easily studied by monitoring changes in the naphthalene excimer fluorescence at 420 nm (Figure 1).


Theme 2: My second research area explores applications of polymer immobilized CDs. There are two sub-themes: waste water remediation using CD polymers to pharmaceuticals in urban water treatment effluent and development of fluorescent CD polymers as sensors for detection of explosives. In this case, a fluorescently-labeled polymer incorporates CD as sites which can trap the explosive analyte (A), quenching the label's fluorescence.

Theme 3: My third research interest is development of molecular imprinted hydrogel polymers. Molecular imprinting is a technique that involves creating cavities within polymeric systems, which retain the conformation of a "template" molecule; a drug compound, for example. A compromise between flexibility and rigidity in the polymer allows for controlled uptake and release of the template along with maintenance of the imprint site conformation in the absence of a template. We are exploring these materials as drug release tools.

For a more detailed profile see myprofile.cos.com/cevans

Member of Canadian Society for Chemistry, American Chemical Society and Inter-American Photochemical Society.

Member of Canadian Society for Chemistry, American Chemical Society and Inter-American Photochemical Society.

S. Zohrehvand, C.H. Evans. "2-Naphthol-Containing -Cyclodextrin-Epichlorohydrin Co-Polymers: Synthesis, Characterization and Fluorescence Studies." Polymer International, 54, 744-753, 2005.

J. van Stam, L. Viaene, C.H. Evans. "Tuning of the -Therthiophene Radical Cation Coupling Reaction Using Mixed Micelles with Varying Charge Densities." ChemPhysChem, 6, 2428-2433, 2005.

S. Sau, B. Solanki, R. Orprecio, J. Van Stam, C.H. Evans. "Higher-Order Cyclodextrin Complexes: the Naphthalene System." J. Inclusion Phenom., 48, 173-180, 2004.

R. Orprecio, C.H. Evans. "Polymer-Immobilized Cyclodextrin Trapping of Model Organic Pollutants in Flowing Water Streams." J. Appl. Polym. Sci., 90, 2103-2110, 2003.

M. Partyka, B.H. Au, C.H. Evans. "Cyclodextrins as Phototoxicity Inhibitors in Drug Formulations: Studies on Model Systems involving Naproxen and Beta-Cyclodextrin." J. Photochem. Photobiol. A: Chem., 140, 67-74, 2001.

C.H. Evans, M. Partyka, J. van Stam. "Naphthalene Complexation by Beta-Cyclodextrin: Influence of Added Short-Chain Linear and Branched Alcohols." J. Inclusion Phenom., 38, 381-396, 2000.

A. Kvaran, A.E. Asgeirsson, C.H. Evans, J.K.F. Geirsson. "1H-NMR, UV-VIS Spectroscopy and Molecular Mechanics Calculations for Chlorine Substituted Stilbenes; Conformational Studies." J. Molec. Struct., 553, 79-90, 2000.