The pure rotational spectrum of 15ND2 observed by millimetre and submillimetre-wave spectroscopy

The pure rotational spectrum of the amidogen radical 15ND2 has been observed between 264 and 1051 GHz with a source-modulation millimetre- and submillimetre-wave spectrometer. A total of 346 transitions were identified, although not all of them were resolved, because of the complexity of the fine and hyperfine structures. The set of spectroscopic parameters determined from the analysis of the spectrum refers to rotational, centrifugal distortion and electron spin-rotation interaction terms. Moreover, the hyperfine constants relative to the electronic spin-nuclear spin interaction for both deuterium and nitrogen nuclei and to the nuclear rotation–nuclear spin interaction for nitrogen were also successfully fitted. This work provides the first laboratory observation and spectroscopic characterization of the fully substituted isotopologue of the astrophysically important species NH2.