Multiple Bonding in Four-Coordinated Titanium(IV) Compounds

Theoretical description (MP2/6-311G* and B3LYP/6-311G*) is presented for hypovalent titanium alkoxide model compounds showing linear ∠Ti−O−C angles. This feature is explained by the existence of a polarized triple Ti−O bond. In contrast, a series of 18 electron germanium derivatives displaying bent ∠Ge−O−C angles contain polarized single Ge−O bonds. The nature of the Ti−O and Ge−O bonds is established by means of natural bond order, atoms-in-molecules theory, and electron localization function analyses.