Rotational Spectroscopic Investigation of the Weak Interaction between CO and N2O

Abstract

Pure rotational spectra of the CO–N2O complex are reported for the first time. Spectra of five isotopomers, i.e., 12C16O–14N14NO, 13C16O–14N14NO, 13C18O–14N14NO, 13C16O–15N14NO, and 13C16O–14N15NO, were measured using a pulsed molecular beam Fourier transform microwave spectrometer. Rotational and quartic centrifugal distortion constants as well as the nuclear quadrupole coupling constants of the terminal and the central 14N nuclei were determined. Comparisons of the nuclear quadrupole coupling constants with the corresponding values of the N2O monomer and with those of other N2O-containing complexes indicate significant electronic charge redistribution at the central nitrogen atom upon complex formation. Structural parameters based on the experimental rotational constants were derived. With the isotopic data available, the orientations of the CO and N2O subunits in the complex could be determined.