Experimental studies for a new family of infrared four-wave mixing spectroscopies

Vibrationally enhanced infrared and vibrationally enhanced Raman four-wave mixing spectroscopy are experimentally explored with the use of several model systems. Studies involving a mixture of chlorobenzene, dichlorobenzene, and deuterobenzene were performed to see whether a simultaneous resonance of a combination band could enhance the Raman ring breathing mode. The results show strong interference effects that may be responsible for a suppression of the Raman resonances, Studies were also carried out in systems of chloroform/deuterobenzene and hexane/deuterobenzene. The latter samples showed intensity increases and line-shape changes that are consistent with vibrational enhancement, The discovery of these enhancements form the basis for developing infrared four-wave mixing as a method for extracting new information about molecular vibrations.