Oxophilic species, early transition metals

Titanium. The high reducing ability and the pronounced oxophilicity of early transition metals in low oxidation states act jointly as a formidable driving force in many transformations. However, such processes are usually hampered by the fact that the metal oxides or alkoxides formed as the inorganic by-products usually resist attempted re-reductions to the active species and thus render catalysis a difficult task. 

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