Photodissociation Spectroscopy of Li−H2O and Li−D2O Complexes

Abstract

The absorption spectra of Li−H2O and Li−D2O, produced by the laser vaporization technique, are examined in the energy region of 10300−11700 cm-1 using a photodepletion method. Vibrationally resolved bands beginning at energies of 10464 and 10525 cm-1 are observed for Li−H2O and Li−D2O, respectively. These peaks are assigned to the transition from the 12A1 ground state to the 22A1 excited state correlating to Li(2P) + H2O(1A1). This transition is more than 4000 cm-1 to the red of the Li (2P−2S) atomic transition. The extensive redshift of the 22A1−12A1 transition is ascribed to the large increase in ionic character in the upper state due to partial electron transfer. The spectrum of the Li−H2O complex exhibits two extra vibronic bands in the region of 300−500 cm-1 above the origin. These bands are tentatively ascribed to the transitions as a result of vibronic interaction between the low-lying excited states.