High-Resolution Stimulated Raman Spectroscopy of 35Cl2, 37Cl2, and 35Cl37Cl

A high-resolution rovibrational Raman spectrum of a sample of Cl 2 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, 35 Cl 2 and 35 Cl 37 Cl, 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.