Tantalum atom reactions with ammonia: Matrix infrared spectra and DFT calculations of the H2TaNH and H2Ta(NH2)2 molecules

► Tantalum atoms react with ammonia to form the metal-ammonia complexes. ► These complexes rearrange to form the imido and amido complexes. ► Isotopic substitutions and DFT frequency calculations are used for identification. ► Reaction mechanism is investigated theoretically.