The microwave spectra of six isotopologues each of 2-chloro-1,1-difluoroethylene and its argon complex are obtained in the 5.6-20.5 GHz region using a combination of broadband chirped pulse and Balle-Flygare cavity Fourier transform microwave techniques. The structure of the halogen substituted ethylene has been determined using a combination of theory and experiment. Argon is found to form a nonplanar complex with this haloethylene, locating in the CICCF cavity, which maximizes its interactions with the heavy atoms in the ethylene subunit. A combined analysis of the chlorine quadrupole coupling constants of the monomer and of the complex allows the sign of the only nonzero off-diagonal component of the quadrupole coupling tensor for the monomer to be determined; thus, the complete tensor for the monomer has been derived. (C) 2014 Elsevier Inc. All rights reserved.