LIF STUDIES OF THE (A)OVER-TILDE(1)A' STATES OF BIOH AND BIOD

Electronic spectra of the recently discovered BiOH and BiOD radicals h ave been studied by means of laser-induced fluorescence measurements i n the 400-1000 nm range. Laser excitation spectra observed in the rang e 430-450 nm are attributed to transitions from the (X) over tilde(1)A ' ground state to the theoretically predicted (A) over tilde(1)A' stat e. Fluorescence spectra from the (A) over tilde(1)A', upsilon'(3) = 0, 1 levels consist of short upsilon''(3) progressions to the lower stat es (X) over tilde(1)A', (X) over tilde(3)A', and (a) over tilde(1)A'. Laser excitation spectra in the range 580-620 nm contain bands with bo th Delta K-a = 0 and Delta K-a = +/- 1 subbands. They are attributed t o hybrid bands of the (A) over tilde(1)A' <-- (X) over tilde(3)A' tran sition. Analyses of the spectra have yielded vibronic energy levels of the (X) over tilde(1)A', (X) over tilde(3)A', (a) over tilde(1)A', an d (A) over tilde(1)A' states of both isotopes and effective rotational constants A - 1/2(B + C) and D-K for some levels. The radiative lifet ime of the (A) over tilde(1)A', 000 state was found to be 0.92 +/- 0.0 3 mu s. (C) 1998 Academic Press.