Characterization of the ground state of Br-2 by laser-induced fluorescenceFourier transform spectroscopy of the B-3 Pi(0+u)-X-1 Sigma(+)(g) system

The laser-induced fluorescence (LIF) spectrum of the B(3)Pi(0+u)-X(1)Sigma( g)(+) system of Br-2 was recorded by Fourier transform spectroscopy (FTS). The LIF spectra were obtained by using continuous-wave dye laser excitation in the spectral region 16 800-18 000 cm(-1). About 1800 rotationally resol ved lines were recorded in 96 fluorescence progressions, originating from t he 10 less than or equal to nu' less than or equal to 22 vibrational levels of the B(3)Pi(0+u) state and involving the 2 less than or equal to nu " le ss than or equal to 29 levels of the X(1)Sigma(g)(+) ground state of the th ree isotopomers of bromine, Br-79(2), Br-81(2), and Br-79,81(2). These data , together with Br-79(2) data from a previous FTS absorption study [S. Gers tenkorn, P. Luc, A. Raynal, and J. Sinzelle, J. Phys. (France) 48, 1685-169 6 (1987)], were analyzed to yield improved Dunham constants for the ground state. A Rydberg-Klein-Rees (RKR) potential energy curve was computed for t he X(1)Sigma(g)(+) State (nu " = 0-29). The equilibrium bond length was fou nd to be Re(X(1)Sigma(g)(+)) = 2.2810213(20) Angstrom, (C) 2000 Academic Pr ess.