Detection of the ν2 bands of CD2 and CH2 by infrared diode laser spectroscopy

Abstract

Five transitions in the ν₂ fundamental band of the CD₂ radical have been detected in the 707 to 718 cm⁻¹ region using a tunable diode laser spectrometer and Zeeman modulation. The CD₂ transitions were of the form N_0,N←N_1,N−1 with N=3 to 7. Two transitions of CH₂ were also observed around 892 cm⁻¹. Analysis of the CD₂ results yields the ν₂ band origin as well as the rotational constant 1/2(B+C) and the spin–spin interaction parameter D for the excited state. The data also provide the basis for a refined determination of the structure and potential parameters of methylene, and the experience gained here in the generation of long absorption paths of the molecule should prove useful in future experiments.