High resolution laser diode spectroscopy of the hot bands of C2HD in the first overtone region of C-H stretching

The frequencies of C2HD hot bands ro-vibrational lines of the first overtone of C-H stretching were measured using tunable diode lasers. To expand the measuring range to the region of the large rotational numbers, a heated gas cell was used. Measurements were made in the range R1-R36 and P2-P14 for the transition (2,0,0,1,0) <- (0,0,0,1,0), and in the range R1-R18 for the transition (2,0,0,0,1) <- (0,0,0,0,1). The rotational parameters of the upper and lower states for the band (2,0,0,1,0) <- (0,0,0,1,0) were determined. The doublet structure of ro-vibrational lines was studied. For the transition (2,0,0,1,0) <- (0,0,0,1,0), a sharp increase in the splitting value was detected at J > 25.