High resolution infrared spectroscopy of monodeutero-oxirane (c-C2H3DO) and analysis of two fundamentals between 820 and 950 cm−1†

Abstract

We report the analysis of the infrared (IR) spectrum of monodeutero-oxirane (c-CH₂CHDO), measured at room temperature at a self-apodized instrumental resolution of 0.0015 cm⁻¹ with the Bruker IFS 125 HR Zürich Prototype spectrometer (ZP 2001), in the range of the ring deformation fundamental ν₁₂ centered at 896.025 cm⁻¹ and the wagging fundamental ν₁₃ centered at 837.36 cm⁻¹. A total of more than 1100 transitions were analyzed and fitted with an effective Hamiltonian which represents the data accurately, within 0.001 cm⁻¹ for ν₁₂ and 0.004 cm⁻¹ for most transitions of ν₁₃. We also report ab initio calculations including parity violation and an extended analysis with a substantial number of further assigned lines in our previously measured pure rotational spectra in the GHz and far infrared range. In combination with ground state combination differences from the IR spectra and further available results, we provide a critical analysis and improved spectroscopic parameters for the vibrational ground state based on more than 3300 assigned rotational transitions. The results are discussed as they pertain to isotopic chirality, molecular parity violation and the astrophysical observation of this isotopomer.