PURE ROTATIONAL SPECTRA OF THE MIXED RARE-GAS VAN-DER-WAALS COMPLEXES NE-XE, AR-XE, AND KR-XE

Pure rotational transitions in the vibrational ground states of various isotopomers of the heteronuclear rare gas dimers Ne-Xe, Ar-Xe, and Kr-Xe have been measured using a pulsed molecular beam cavity microwave Fourier transform spectrometer. Rotational and centrifugal distortion constants have been obtained, and have yielded estimates of the lengths of the van der Waals bonds and of their harmonic vibration frequencies. Effects due to nuclear quadrupole coupling have been observed in Xe-131-containing complexes and have yielded the corresponding nuclear quadrupole coupling constants. The electric molecular dipole moments of the complexes have been estimated from the excitation pulse lengths, optimized for maximum signal strength (pi/2 condition).