This Research in Undergraduate Institutions grant is in the general area of analytical and surface chemistry and in the subfield of separations science. Professor Robert Kooser of Knox College will use electron spin resonance studies of probe molecules to follow the dynamics of structural changes in flowing liquid chromatographic systems. The research will advance the knowledge of the structure of the liquid/solid interface and the structure of stationary phases used for separations. In addition, the research program will introduce three undergraduates each summer to the various aspects of instrumental analysis, computer data acquisition and spectroscopy. The multidisciplinary aspect of this study will allow for a well designed undergraduate research experience. Using the loop gap resonator electron spin resonance cell, Professor Kooser and his students will study the structure of common stationary phase materials while under flow. The research group at Knox College has been successful in synthesizing new types of spin label functionalities directly at particular positions in silane surface modifier compounds. In this study, the nitroxyl probe functionality will be directly bonded in low concentrations of alkyl chains attached to the silica in a reversed phase stationary phase. By constructing a flow cell in the loop gap resonator, the mobility of the particular spin probe as a function of size and position may be monitored. This will allow determination of structure for many species under conditions never probed previously.
