JOSEPH P. MESSINGER, GREGORY S. KNOWLTON, KATHRYN M. SUNDHEIM, HELEN O. LEUNG AND MARK D. MARSHALL, Department of Chemistry, Amherst College, P.O. Box 5000, Amherst, MA 01002-5000.
Chirped-pulse and Balle-Flygare spectrometers are used to obtain Fourier transform microwave spectra of 2-chloro-1,1-difluoroethylene and its complex with argon from 5.5 to 21.0 GHz, allowing for the geometries of both species to be determined. A total of six isotopologues are observed each for the monomer and dimer, including the most abundant species, the singly-substituted 37Cl and two singly-substituted 13C isotopologues in natural abundance, and deuterated versions of both the 35Cl and 37Cl species using an isotopically enriched sample. Similar to the previously studied argon-haloethylene complexes, the argon shows a preference for close contact with heavier atoms. Tunneling of the argon between two equivalent non-planar structures, similar to that in argon- cis -1,2-difluoroethylene, is not observed in this complex.