Rotational spectra, structure, and intramolecular force field of the Hg–OCS van der Waals complex

Abstract

Pure rotational spectra of the mercury–carbonyl sulfide complex have been observed by a pulsed-nozzle Fourier-transform microwave spectrometer, which has been recently constructed. The structure of the complex is found to be T-shaped, which is the same as the rare-gas–carbonyl sulfide complexes analogous to this system. The mercury–carbon distance and the Hg–C–O angle have been determined to be 3.7075(2) Å and 86.98(1) deg, respectively, for 202Hg–OCS from the rotational constants. Harmonic force constants of the van der Waals modes have been derived by the centrifugal distortion constants. The electric quadrupole coupling constants for 201Hg–OCS have also been determined and the values indicate small perturbation on the electric charge distribution of the mercury atom by complex formation.