Raman‐induced kerr effect spectroscopy of solutions

Abstract

AbstractRaman‐induced Kerr effect spectroscopy (RIKES) as a tool for the investigation of species in solution is presented. RIKES has proved to be a particularly useful probe for Raman modes of molecules in solution because control of the polarizations of the interacting laser fields allows non‐resonant solvent contributions to the background to be minimized. New techniques to subtract laser power fluctuations from the signal have further increased the sensitivity of RIKES. Spectra of carbon tetrachloride, benzene and the hydroxide ion are presented to show the utility of RIKES for investigating solutions. The ability to decrease background noise by controlling the polarization of the pump laser was demonstrated by studying the 459 cm−1 carbon tetrachloride resonance. Concentration studies on benzene in carbon tetrachloride showed a narrowing of the 992 cm−1 mode of benzene as its concentration was decreased. The sensitivity of the technique is demonstrated with spectra recorded on 0.01 M benzene in carbon tetrachloride. The 3620 cm−1 OH− resonance is presented for a 10 M solution of NaOH in water. A nearby water resonance makes the OH− mode difficult to see at lower concentrations. Polarization tuning was not able to improve the RIKES sensitivity in this case.