STIMULATED RAMAN-SCATTERING ACTIVITY OF ORGANIC-COMPOUNDS

The stimulated Raman scattering (SRS) activity of over one hundred org anic compounds was investigated at room temperature. Spectra were obta ined successfully for the colourless neat liquids but not for the soli d chemicals in solution, and their SRS shifts were measured systematic ally. The results confirmed that SRS Stokes shifts are usually the sam e as those observed in spontaneous Raman scattering, with occasional d ifferences in frequency from the strongest spontaneous Raman bands. Em pirical trends have been observed in functional group recognition, com pound classification, degenerate vibrational modes, substituent group effects, hydrogen bonding and concentration threshold. Other new obser vations such as multiple peaks, exceptional SRS activity and distribut ed spectra are also reported. SRS offers several advantages over norma l Raman spectroscopy in industrial process monitoring, and a potential ly interesting scope of analytical utility is discussed.