Rotational Spectroscopic Investigation of the Weak Interaction between CO and N(2)O

Pure rotational spectra of the CO-N(2)O complex are reported for the first time. Spectra of five isotopomers, i.e., (12)C(16)O-(14)N(14)NO, (13)C(16)O-(14)N(14)NO, (13)C(18)O-(14)N(14)NO, (13)C(16)O-(15)N(14)NO, and (13)C(16)O-(14)N(15)NO, 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 (14)N nuclei were determined. Comparisons of the nuclear quadrupole coupling constants with the corresponding values of the N(2)O monomer and with those of other N(2)O-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 N(2)O subunits in the complex could be determined. Copyright 1999 Academic Press.