High-Resolution Study of the BaI A(2)Pi Electronic State.

Near-infrared and visible spectra of the A(2)Pi-X(2)Sigma(+), C(2)Pi(1/2)-A(2)Pi(1/2), C(2)Pi(1/2)-B(2)Sigma(+), and C(2)Pi(1/2)-X(2)Sigma(+) band systems of the BaI molecule were recorded by using Fourier transform spectroscopy (FTS). The spectra were produced from the chemiluminescent reaction Ba + I(2) and also by using laser-induced fluorescence (LIF) technique in which the laser sources were a Ti:sapphire single-mode laser, a dye single-mode laser, and a Kr(+) multimode ion laser. Resolved rotational data, originating from 19 vibrational levels (0 </= v </= 5 and 7 </= v </= 19) of the A(2)Pi state, 24 vibrational levels (0 </= v </= 18 and 20 </= v </= 24) of the X(2)Sigma(+) state, and 8 vibrational levels (1 </= v </= 2 and 9 </= v </= 14) of the C(2)Pi state, were used in the final analysis. Previously recorded data for the B(2)Sigma(+)-X(2)Sigma(+) and C(2)Pi-X(2)Sigma(+) systems, taken from R. F. Gutterres, J. Vergès, and C. Amiot, J. Mol. Spectrosc. 196, 29-44 (1999) and from C. A. Leach, A. A. Tsekouras, and R. N. Zare, J. Mol. Spectrosc. 153, 59-72 (1992), were added to the present work data field. Accurate and improved molecular constants, for the X(2)Sigma(+), B(2)Sigma(+), A(2)Pi, and C(2)Pi states, were derived from a simultaneous treatment of the whole data set. Copyright 2000 Academic Press.