Haruki Ishikawa

Chioko Nagao, and Naohiko MIKAMI Department of Chemistry, Graduate School of Science, Tohoku University Aoba-ku, Sendai 980-8578, JAPAN

Our observation of highly excited vibrational levels of HCP has attracted many theoretical interests. In the case of HCP, it was revealed that an anharmonic resonance between the bend and the CP stretch modes plays an important role in the vibrational dynamics from both the experimental and theoretical studies. The agreement between experimental and theoretical analyses of the highly excited vibrational levels was excellent.
In our previous experimental observation and analysis, vibrational levels in rather low energy region are treated. In much higher energy region, the interaction between the bend and the CH stretch modes becomes strong. To extend our experimental study on the highly excited levels of HCP, it is necessary to get the information about levels which involves the excitation of CH stretch. Thus, we have developed an IR-UV-DF and IR-UV-SEP spectroscopies. In both techniques, we use the IR-UV double resonance excitation as a pump scheme of the DF and/or SEP spectroscopies. As a result, highly excited vibrational levels involving the CH stretch excitation could be observed for the first time.