Abstract We utilized the high resolution of microwave Fourier transform spectroscopy to investigate the 14N-hyperfine structure of trans-2,2,2-trifluoroethylamine, CF3CH2NH2, trans-isopropylamine, CH3CHNH2CH3, and aminoethanole, HOCH2CH2NH2, and the amino deuterated isotopomers trifluoroethylamine-d2 and isopropylamine-d2. The complete coupling tensor of trifluoroethylamine could be determined. We found that the fluorine atoms have a distinct effect on the nitrogen electronic surrounding of the named molecule, presumably through a hydrogen bridge bond between two of these atoms and the amino protons. For isopropylamine and aminoethanole wrong values of the coupling constants known in the literature could be corrected