Diode laser spectrum of HCCl near 5 μm: The ν2 fundamental and accompanying hot bands☆

Abstract The CC stretching band ν 2 of iodoacetylene has been studied by tunable laser spectroscopy in the range of 2037–2071 cm −1 . The hot bands associated with the low-lying bending vibrations ν 4 and ν 5 were observed. For the Π-Π hot bands, the splitting caused l -type doubling was resolved for high J transitions. For the fundamental band the hyperfine splittings due to the 127 I nuclear quadrupole moment were clearly observed for R (0) and P (1) transitions. Combination of these diode laser spectra with the microwave data allows precise determination of the constants in the ground and excited vibrational states.