Microwave spectrum and quadrupole coupling constant tensor of 3-chlorothiophene

Abstract

Microwave spectra of the two 35Cl and 37Cl isotopic species of 3-chlorothiophene have been measured in the frequency region of 8–22 GHz. Only a-type R-branch transitions were assigned. One hundred eighty-eight quadrupole hyperfine component spectra for the 49 transitions of the 35Cl species and 169 quadrupole hyperfine component spectra for the 45 transitions of the 37Cl species were measured. The rotational constants of the ground state were determined to be A = 7144.19 ± 0.41, B = 1508.3654 ± 0.0031, and C = 1245.0304 ± 0.0031 MHz for the 35Cl species; and A = 7143.22 ± 0.37, B = 1464.1853 ± 0.0025, and C = 1214.6826 ± 0.0025 MHz for the 37Cl species. From the quadrupole hyperfine splittings of the chlorine nucleus, the nuclear quadrupole coupling constants in the principal axes system were determined to be χ aa = −72.62 ± 0.16, χ bb = 34.59 ± 0.90, and χ cc = 38.03 ± 0.91 MHz for the 35Cl species; and χ aa = −57.57 ± 0.16, χ bb = 27.46 ± 0.75, and χ cc = 30.11 ± 0.76 MHz for the 37Cl species.