Infrared Laser Spectroscopy

William Marsh Rice University, Houston TX

Investigators

Abstract

Dr. Robert F. Curl of Rice University is funded for his research on infrarerd laser spectroscopy by the Physical Chemistry Program of the Chemistry Division. High resolution laser infrared spectroscopy of cyanomethylene (HCCN), hydroxymethyl, methoxy, vinoxy. and triplet vinylidene will be used to analyze the electronic structures, potential surfaces, and internal dynamics. Interest in HCCN eminates from the low activation to bending about the HCC angle; an experimentally derived potential for this bending motion will be generated. Jahn-Teller distorions in methoxy should be particularly evident in the unsymmetrical CH stretching modes. The experimentally determined potential surface will be used to elucidate the Jahn-Teller effect. Triplet vinylidene is a high energy isomer of acetylene. The rotational spectrum will be measured so that the structure of this isomer can be unequivocally assigned. The tuning range of cw quantum cascade lasers will be increased so as to make such lasers more ueful for general spectroscopic purposes by operating them in an extended cavity laser configuration. The value of the wider tuning window in infrared laser spectroscopy will be demonstrated experimentally. The use of high resolution infrared vibrational and rotational spectra in structure determinations of significant radicals provides important insight into basic bonding and structural questions. Many such radicals are important in chemical processes and are highly reactive, and are therefore difficult to analyze because of fleeting lifetimes. The studies by Dr. Curl at Rice University will provide novel measurements of such radicals that will advance our basic understanding of important chemical radicals, with respect to their structure and their reactivity.