FOURIER-TRANSFORM MICROWAVE SPECTROSCOPY OF HG-CO2

Pure rotational spectra of the mercury-carbon dioxide complex have been observed by a Balle-Flygare-type Fourier-transform microwave spectrometer with a high temperature pulsed valve. From the nuclear spin statistics associated with the oxygen atoms of CO2, the complex has been found to be T-shaped with C2-upsilon symmetry, as in the analogous rare gas-carbon dioxide complexes. The rotational constants, B and C, and the harmonic force constants for the van der Waals (vdW) modes have been determined from a nonlinear least-squares fit of the transition frequencies. The mercury-carbon distance has been derived to be 3.695 angstrom from the determined rotational constants. The permanent dipole moment of the complex has been determined to be 0.107 (3) from Stark effect measurement, where the value in parentheses is twice the standard deviation.