Collisional deactivation of vibrationally highly excited polyatomic molecules. III. Direct observations for substituted cycloheptatrienes

摘要

Vibrationally highly excited ethylhyphen;cycloheptatriene (41thinsp;600 cmminus;1) and isopropylhyphen;cycloheptatriene (41thinsp;800 cmminus;1) molecules in the electronic ground state have been prepared by UV laser excitation inducing onehyphen;photon absorption and subsequent internal conversion. Collisional energy loss of these molecules has been followed directly by hot UV absorption spectroscopy. Average energies transferred per collision lang;Dgr;Erang; have been determined for a series of bath gases. lang;Dgr;Erang; values were found, for a given bath gas, to increase very slightly with the size of the excited molecule.