The laser magnetic resonance spectrum of the ν2 band of the methylene radical CH2

Abstract

Ten rotation–vibration transitions in the ν₂ (bending) fundamental band of CH₂ in its ³B₁ ground electronic state have been measured and assigned using the technique of intracavity CO₂ laser magnetic resonance (LMR) spectroscopy in the region 880–1090 cm⁻¹. Using the present data, and the microwave and far‐infrared LMR measurements of pure rotational transitions, an effective bending potential energy curve has been derived for CH₂ using the semirigid bender Hamiltonian. The bending frequency of CH₂ is determined to be ν₂=963.0987(4) cm⁻¹, which is considerably lower than previous theoretical and experimental estimates.