Tetrakis-(dimethylamino)-titanium (TDMAT) is a deposition precursor for titanium nitride and titanium carbonitride diffusion barriers. We investigated the reaction of TDMAT with the Si(100) surface because of its crucial impact on the growth of diffusion barrier films and on the interface formation. A combination of density functional calculations and infrared (IR) spectroscopy suggests that TDMAT dissociatively adsorbs on Si(100). Such process involves the formation of a Ti-Si bond upon cleavage of a Ti-N bond. The reactivity of the Ti-N bond was also observed during TDMAT adsorption on ammonia-covered surfaces, where our spectroscopic results indicate that transamination reactions occur. In addition to the possibility of Ti-N scission during the first stages of adsorption, the cleavages of both a C-H bond and a C-N bond are considered as alternative pathways of adsorption. Spectroscopic evidence of Si-H bond formation upon TDMAT adsorption indicates that scission of the C-H bond is possible, although as a minor channel. In contrast, we did not find any experimental evidence of Si-CH₃ bond formation, in agreement with the theoretical prediction that scission of the C-N bond is thermodynamically stable but kinetically hindered. Due to the current importance of zirconium-, hafnium-, and tantalum-containing compounds for technological applications, the dissociative adsorption of their alkylamino compounds is investigated by theoretical methods and compared to TDMAT. Elucidation of the first stages of adsorption will allow a better control of thin film growth processes.