SPECTROSCOPY AND ELECTRON DETACHMENT DYNAMICS OF C-4(-), C-6(-) AND C-8(-)

Resonant multiphoton detachment spectroscopy has been used to obtain v ibrationally resolved spectra of the C (2) Pi <-- X (2) Pi electronic transitions In C-4(-), C-6(-), and C-8(-). Transitions due to vibratio nal excitations in the totally symmetric stretching modes as well as t he bending modes are observed. The electron detachment dynamics subseq uent to multiphoton absorption are studied by measuring the electron e mission time profiles and electron kinetic energy distributions. The o bservation of delayed electron emission combined with the form of the electron kinetic energy distributions indicates that these species und ergo the cluster equivalent of thermionic emission. This interpretatio n is supported by comparing the experimental results to a microcanonic al model for cluster thermionic emission. (C) 1996 American Institute of Physics.