A Theoretical Study of Amine Bonding in Titanium Alkoxide Adducts

DFT calculations were carried out on Ti-2(OCH3)(8) (NH2CH3)(2) and Ti-2(OCH3)(8)(NH3)(2), which are model compounds for the previously isolated amine adducts Ti-2(OR)(8)(NH2 R')(2). The calculations show that the Ti-N bond strength is weak; however, coordination of the amine to the metal center is supported by a N-H center dot center dot center dot O hydrogen bond of the amine with the neighboring alkoxo ligand. The Ti-N interaction is purely sigma in nature, while the Ti-O interactions include both sigma and pi contributions. The lowest unoccupied molecular orbitals are mainly localized on Ti t(2g)-like orbitals.