Microwave spectrum and structure of the dimethylamine dimer: Evidence for a cyclic structure

Rotational spectra have been measured for six isotopomers of the dimethylamine dimer using a Fourier‐transform microwave spectrometer. No tunneling splittings were observed for either the a‐ or c‐type rotational transitions and the spectra could be fit to a rigid rotor Hamiltonian including centrifugal distortion terms. Possible dimer structures are discussed and compared to the experimentally determined moments of inertia, dipole moments, and nuclear quadrupole coupling constants. A cyclic structure with Cs symmetry was found to best reproduce the inertial data. The structure of the dimethylamine dimer is compared to the theoretical and experimental structures for the ammonia dimer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70922/2/JCPSA6-100-5-3377-1.pd