Ammonia-Borane Derived BN Fragments Trapped on Bi- and Trimetallic Titanium(III) Systems

Abstract

Titanium(III) complexes containing unprecedented (NH2BH2NHBH3)2‒ and {N(BH3)3}3‒ ligands have been isolated and their structures elucidated by a combination of experimental and theoretical methods. The treatment of the trimethyl derivative [TiCp*Me3] (Cp* = η5-C5Me5) with NH3BH3 (3 equiv) at room temperature gives the paramagnetic dinuclear complex [{TiCp*(NH2BH3)}2(μ-NH2BH2NHBH3)], which at 80 ºC leads to the trinuclear hydride derivative [{TiCp*(μ-H)}3{μ3-N(BH3)3}]. The bonding modes of the anionic BN fragments in those complexes as well as the dimethylaminoborane group trapped on the analogous trinuclear [{TiCp*(μ-H)}3(μ3-H)(μ3-NMe2BH2)] have been studied by X-ray crystallography and density functional theory (DFT) calculations.