DFT calculations were employed to investigate transamination during metalorganic chemical vapor deposition (MOCVD) of transition metal nitrides films, such as titanium nitride (TiN) and tantalum nitride (TaN). The calculated energetics and rate constants for the ligand exchange of tert-butylimidotris(dimethylamido) tantalum (TBTDMT) with NH3 demonstrated that NH3 addition to form the ammonia adduct, TBTDMT center dot NH3, proton transfer and dissociation of dimethylamine to afford net transamination of the dimethylamido ligand are facile even at low temperature (-300 degrees C). The transamination of the tert-butylimido ligand, however, was relatively slow at those temperatures but became facile at temperatures appropriate for CVD growth (-600 degrees C). Rapid transamination is consistent with lower temperature for growth of TaN by MOCVD in the presence of NH3, efficient removal of carbon-containing ligands, and incorporation of higher levels of nitrogen in the resulting films. (C) 2009 Elsevier B.V. All rights reserved.