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

摘要

Simple exposure of a hexane solution of [TiCp*Me_3] (Cp*=η~5-C_5Me_5) to an atmosphere of commercially available and inexpensive forming gas (H_2/N_2 mixture, 13.5-16.5% of H_2) at room temperature leads to the methylidene-methylidyne-nitrido cube-type complex [(TiCp*)_4(μ_3-CH)(μ_3-CH_2)(μ_3-N)_2] via dinitrogen cleavage. This paramagnetic compound reacts with [D_1]chloroform to give the titanium(IV) methylidyne-nitrido species [(TiCp*)_4(μ_3-CH)_2(μ_3-N)_2], whereas its one-electron oxidation with AgOTf or [Fe(η~5-C_5H_5)_2](OTf) (OTf=O_3SCF_3) yields the diamagnetic ionic derivative [(TiCp*)_4(μ_3-CH)(μ_3-CH_2)(μ_3- N)_2](OTf). The μ_3-nitrido ligands of the methylidyne-nitrido cubane complex can be protonated with [LutH](OTf) (Lut=2,6-lutidine) or hydrogenated with NH_3·BH_3 to afford μ_3-NH imido moieties.