The experiments were carried out using the negative-ion photoelectron imaging spectrometer described elsewhere. A CO2 or O2 carrier gas at a backing pressure of ~1.4 atm was passed over a saturated solution of elemental sulfur dissolved in CS2, kept at room temperature. The 532 nm results presented here were obtained with CO2 carrier gas, while O2 was used in the 355 nm and 611 nm experiments for increased production of the SO  ions. The precursor gas mixture was expanded into a high-vacuum ion-source chamber (base pressure 2×10 7 torr; operational pressure 2-3×10 -5 torr) through a pulsed supersonic nozzle (General Valve, Inc., Series 9) operated at a 50 Hz (532 and 355 nm) or 20 Hz (611 nm) repetition rate matching that of the laser.