Microwave Spectrum and Dipole Moment of 1,3‐dioxolane in the Hindered‐Pseudorotation States v = 0, 1, 2, and 3

Abstract

The microwave spectrum of 1,3‐dioxolane (C₃H₆O₂) in the ground and first three excited states of hindered pseudorotation was studied. The transitions corresponding to the μ_b, μ_c, and μ_a components of the dipole moment were identified. The spectrum was analyzed using numerical diagonalization of the effective rotational Hamiltonian for four interacting states of hindered pseudorotation. The rotational constants, centrifugal distortion constants, the constants of interaction between general rotation and hindered pseudorotation, and the distances between the quasidegenerate vibrational levels Δ₀₁ = 64840.5, Δ₁₂ = 122231.7 and Δ₂₃ = 119732.7 MHz are determined. From the Stark effect of microwave transitions, the dipole moment components (in Debye units) in the hindered‐pseudorotation states v = 0, 1, 2, and 3 are determined: 〈0|μ_b|0〉 = 〈1|μ_b|1〉 = 1.22, 〈2|μ_b|2〉 = 1.20, 〈3|μ_b|3〉 = 1.21, 〈0|μ_c|1〉 = 0.77, 〈2|μ_c3〉 = 0.66, and 〈1|μ_a|2〉 = 0.19.