b1Σ+ Emissions from group V–VII diatomic molecules. b 0+ → X1 0+, X2 1 emissions of AsI and SbI

Abstract Chemiluminescence from the b 0 + → X 1 0 + band system of AsI and of the b 0 + → X 1 0 + , X 2 1 systems of SbI in the near-infrared spectral region has been observed in a discharge flow system. Analysis of the spectra led to the spectroscopic constants (in cm −1 ) of AsI: ω e (X 1 , X 2 ) = 257 ± 2, ω e x e (X 1 , X 2 ) = 0.82 ± 0.2, T e (b 0 + ) = 11738 ± 5, ω e (b 0 + ) = 271 ± 2, ω e x e (b 0 + ) = 0.66 ± 0.2, and of SbI: T e (X 2 1) = 965 ± 10, ω e (X 1 , X 2 ) = 206 ± 6, T e (b 0 + ) = 12328 ± 10, ω e (b 0 + ) = 211 ± 6. The intensity ratio of the two sub-systems b 0 + → X 2 1 and b 0 + → X 1 0 + was found to be ≈0.013 in the case of SbI and ⩽ 0.01 for AsI.