PHOTODISSOCIATION SPECTROSCOPY OF MG+-AR

Mg+-Ar ion-molecule complexes are produced in a pulsed supersonic nozz le cluster source. The complexes are mass selected and studied with la ser photodissociation spectroscopy in a reflectron time-of-flight mass spectrometer system. An electronic transition assigned as X 2SIGMA+-- >2PI is observed with an origin at 31387 cm-1 (vac) for Mg-24+-Ar. The Mg-24+-Ar spectrum is characterized by a 15 member progression with a frequency (omega(e)') of 272 cm-1. An extrapolation of this progressi on fixes the excited state dissociation energy (D0') at 5552 cm -1. Th e corresponding ground-state value (D0'') is 1270 cm-1 (3.6 kcal/mol). The 2PI1/2,3/2 spin-orbit splitting is 76 cm-1.