HIGH-RESOLUTION STUDY OF THE A-1-X0+ EMISSION SYSTEM OF BISMUTH HYDRIDE

The 0-0 band of the A 1-X 0+ electronic transition of BiH near 2.02 μm has been recorded in emission using a Bomem Fourier-transform spectrometer. With a spectral resolution of 0.02 cm-1 the hyperfine structure of the rotational lines due to magnetic hyperfine splittings in the A 1 state is well resolved for a number of lines in all three branches. The two states involved can be considered as the Ω = 1 and 0 spin components of the X 3Σ- ground state of BiH. The spectrum was fitted using an effective Hamiltonian and the following molecular constants were obtained (in cm-1): B0 = 5.13678(17), 104D0 = 1.900(21), λ0 = 2473.4224(38), 102λD = 3.7605(23), 102λ0 = 4.00(75), (b + c) = -0.11776(60), 103b = 2.5(84), with error limits of 3σ. © 1990.