This project is a continuation of the research we started in fall 2009. We will investigate the host/guest chemistry of cyclodextrin/spiropyran and cyclodextrin/merocyanine systems. Spiropyran and merocyanine may potentially be used in the development of new materials for photochromic switches, photochromic lenses (optometry), fluorescent biomarkers, and drug delivery devices.

Spiropyran is a colorless molecule in solution and converts to merocyanine—a colored molecule in solution—upon absorption of ultraviolet light. However, it is known that the interconversion of spiropyran to merocyanine is thermally unstable. We have bound these molecules in the cavity of cyclodextrins in order to provide a more stable microenvironment. We have used absorption spectroscopy to study the kinetics of the interconversion of spiropyran into merocyanine. We acquired absorption spectra and we now propose to study emission spectroscopy in order to fully characterize the absorption and emission of light by these molecules. Students will prepare solutions, acquire data, analyze spectra, and present their results at regional meetings.