Vibrational–Rotational Analysis of the Hot 2ν2–ν2 Band of the 15NH2D and 15NHD2 Molecules

High-resolution spectra of the $$2{{\nu }_{2}}{-} {{\nu }_{2}}$$ hot band of the 15NH2D and 15NHD2 molecules are investigated for the first time. The analysis is carried out based on the ground state combination difference method. As a result, the energy structure of the inversion-vibrational state ($${{{v}}_{2}}$$ = 2, s) has been obtained for each of the molecules under study and more than 480 vibrational–rotational transitions belonging to the studied hot bands have been found. Values of the upper energy levels determined based on the position of lines are used as initial data for the determination of spectroscopic parameters of the ($${{{v}}_{2}}$$ = 2, s) state.