STIMULATED RAMAN PUMPING OF C-2(-) PROBED VIA RESONANT 2-PHOTON DETACHMENT

We demonstrate for the first time that stimulated Raman pumping (SRP) can be used to vibrationally excite gas-phase negative ions. Results a re presented for C-2(-), in which stimulated Raman pumping excites a r otationally resolved transition between the upsilon = 0 and upsilon = 1 levels of the ground (2) Sigma(g)(+) state; this excitation is monit ored by resonant two-photon detachment through the excited B 2 Sigma(u )(+) state. At least 35% conversion to the upsilon = 1 level was achie ved in this study. It is expected that this method is quite generally applicable and will provide an excellent tool for the study of the vib rational spectroscopy of negative ions.