Laser excitation and photoionization spectroscopy of the AO⁺ and B1 states of indium monoiodide: Ground state dissociation energy and photodissociation yield of In(6s²S_1/2)

The dissociation energy of the InI ground state (X¹Σ⁺(O⁺)) and the relative yield of In(6s ²S_1/2) from the photodissociation of InI by sequential two-photon absorption have been measured by laser-induced fluorescence and excitation spectroscopy in the 390-431 nm region. Laser excitation spectroscopy and photoionization experiments demonstrate that the XO⁺ dissociation energy is 25 340±90cm^-1, which agrees with the value suggested by Vempati and Jones [J. Mol. Spectrosc. 127, 232 (1988)] if the InI ground state is covalent. Seven previously unreported vibrational bands of the InI(B←X) transition have been observed and the molecular emission spectra indicate that the B ³Π₁(I) state is predissociated above ν = 6. Splitting between the fine structure levels of the In np ²P_1/2,3/2 (15≤n≤17) states has also been measured by fluorescence suppression spectroscopy, following the three photon excitation of InI in the 450-470 nm interval.