ABSORPTION AND FLUORESCENCE-SPECTRA OF METHYL SALICYLATE IN THE VAPOR-PHASE

Methylsalicylate (MSA) in vapor state shows two fluorescences originating from two different ground state species. The short wavelength emission is ascribed to free MSA molecules with open hydrogen bonds, whereas the blue fluorescence is due to closed MSA. From a study of the temperature dependence of the short-to-long wavelength fluorescence intensity ratio, the energy required for ring opening is found to be 15 kJ mol-1. © 1979.