Raman Spectroscopy: a Structural Probe of Solute-Solvent Interactions in Ethyl 4-(dimethylamino)benzoate
Musilli M. Mitambo and Glen R. Loppnow
Abstract
Raman spectra of ethyl 4-(dimethylamino)benzoate (DMABEE) were recorded in 18 solvents of varying polarity and hydrogen bonding strength to elucidate the molecular mechanism of solute-solvent interactions in condensed phase. Frequency shifts were observed in the vibrational frequencies of the C=O stretching, the C-O stretching, and the OCO bending modes, as a function of increasing solvent acceptor number. A molecular model of DMABEE-solvent interaction is proposed based on solute-solvent hydrogen bonding and pi-pi interactions. These results suggest that vibrational spectroscopy provides a mode-specific measure of solute-solvent interactions.