Nuclear quadrupole hyperfine structure in the rotational spectra of HCCH–N2O and Ar–N2O

Abstract

Hyperfine structure in N₂O-containing weakly bound complexes is fully analysed for the first time in the rotational spectra of HCCH–N₂O and Ar–N₂O using a pulsed molecular beam Fourier-transform microwave spectrometer; the nuclear quadrupole coupling constants for the two ¹⁴N nuclei indicate that while Ar affects slightly the electric field gradients surrounding the nitrogen nuclei during complexation with N₂O, HCCH changes the charge distribution surrounding the central nitrogen nucleus in the HCCH–N₂O complex significantly; thus, the use of nuclear quadrupole coupling constants to obtain angular information may not be acceptable for complexes in which the field gradient of the quadrupolar nucleus is distorted in the presence of another molecule.