High-Resolution Stimulated Raman Spectroscopy of Cl2, Cl2, and ClCl

A high-resolution rovibrational Raman spectrum of a sample of Cl₂ has been recorded at room temperature using a quasi-cw stimulated Raman technique. Three Q-branch structures belonging to the fundamental vibrations of the three chlorine isotopomers present in the sample in natural abundances and two weaker Q branches belonging to the first hot bands of the two more abundant isotopomers, ³⁵Cl₂ and ³⁵Cl³⁷Cl, have been observed. Lines with values of J up to 60 for the fundamentals and 50 for the hot bands have been measured in these fully resolved structures. Some additional lines belonging to O and S branches of the fundamentals and hot bands have also been recorded. The analysis of these data has rendered a new and more precise set of rotational molecular constants and band origins for the first three vibrational states of the chlorine isotopomers.