ROTATIONAL SPECTRUM AND STRUCTURE OF A FURAN (ARGON)2 VANDERWAALS COMPLEX

Two stable conformers of the complex of furan with two argon atoms have been found with molecular mechanics calculations. Pure rotational transitions of one of the predicted conformers have been identified in the frequency range 8-18 GHz with a pulsed nozzle beam Fourier transform microwave spectrometer. Rotational constants A = 4187.6694(17) MHz, B = 493.8114(32) MHz and C = 486.5645(31) MHz have been fitted to 27 measured transition frequencies. They are compatible with the symmetric conformer that exhibits an argon atom on both sides of the molecular plane of furan. Two structural parameters have been determined which locate the argon atom with respect to the furan molecule in the complex.