Microwave Spectrum and Dipole Moment of Dimethylnitrosamine

The microwave spectrum of the (CH 3 ) 2 NNO and (CH 3 ) 2 15 N 15 NO species have been studied and the rotational constants evaluated. By comparison of the inertia defects of the two species it can be stated that the nuclear frame of the molecule is planar, which is in agreement with the reported electron diffraction results. The dipole moment of the (CH 3 ) 2 15 N 15 NO species has been determined. Further studies on the internal rotation of the two methyl tops are in progress together with the analysis of the spectra of other isotopically substitued species.