Cleavage of Dinitrogen from Forming Gas by a Titanium Molecular System under Ambient Conditions

Abstract

Simple exposure of a hexane solution of [TiCp*Me3](Cp* = h5-C5Me5) to an atmosphere of commercially available and inexpensive forming gas (H2/N2 mixture, 13.5-16.5 % of H2) at room temperature leads to the methylidene-methylidyne-nitrido cube-type complex [(TiCp*)4(m3-CH)(m3-CH2)(m3-N)2] via dinitrogen cleavage. This paramagnetic compound reacts with [D1]chloroform to give the titanium(IV) methylidyne-nitrido species [(TiCp*)4(m3-CH)2(m3-N)2], whereas its one-electron oxidation with AgOTf or [Fe(h5-C5H5)2](OTf) (OTf = O3SCF3) yields the diamagnetic ionic derivative [(TiCp*)4(m3-CH)(m3-CH2)(m3-N)2](OTf). The m3-nitrido ligands of the methylidyne-nitridocubane complex can be protonated with [LutH](OTf)(Lut = 2,6-lutidine) or hydrogenated with NH3·BH3 to afford m3-NH imido moieties.