LIFETIME MEASUREMENTS OF SELECTIVELY EXCITED MOLECULAR-LEVELS OF THE A(3)SIGMA(-)(0(+)) AND A'(1)SIGMA(+)(0+) ELECTRONIC STATES OF BICL

Fluorescence lifetimes for emission from specific (v', J') rovibration al levels of the BiCl A (3) Sigma(-)(0(+)) states have been measured f or the first time by laser-induced fluorescence. Collision-free lifeti mes for various rovibrational levels (v' J') of the BiCl A (3) Sigma()(0(+)) state have been measured. No significant variations were found for the collision-free lifetimes for different rotational transitions in the v' = 0-9 interval of vibrational levels of the A (3) Sigma(-)( 0(+)) state studied. A collision-free fluorescence radiative lifetime of tau(0) similar or equal to 0.64 mu s is proposed for the BiCl A (3) Sigma(-)(0(+)) state, and values for quenching rate constants in the range k(Q) similar or equal to (3 +/- 2) x 10(-12)-(26 +/- 2) x 10(-12 ) cm(3)/molecule s(-1) in the spectral region studied were obtained. C ollision-free lifetimes for various rovibrational levels (v', J') of t he A' (1) Sigma(+)(0(+)) BiCl state have been measured. No significant variations were found for the collision-free lifetimes for different rotational transitions in the vibrational level interval v' - 3-5 of t he A' (1) Sigma(+)(0(+)) state. A collision-free fluorescence radiativ e lifetime of tau(0) similar or equal to 2.75 mu s is proposed for the BiCl A' 1 Sigma(+)(0(+)) state, and values for quenching rate constan ts of k(Q) similar or equal to (1.32 +/- 0.14) x 10(-11) cm(3)/molecul e s(-1) in the spectral range studied were obtained. From the calculat ed Franck-Condon factors for the v'-v '' transitions of both systems a nd our radiative lifetimes, electronic transition momenta have been ob tained.