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

Simple exposure of a hexane solution of [TiCp*Me ] (Cp*=η -C Me ) to an atmosphere of commercially available and inexpensive forming gas (H /N mixture, 13.5-16.5 % of H ) at room temperature leads to the methylidene-methylidyne-nitrido cube-type complex [(TiCp*) (μ -CH)(μ -CH )(μ -N) ] via dinitrogen cleavage.

Catalytic borylation of methane.

Despite steady progress in catalytic methods for the borylation of hydrocarbons, methane has not yet been subject to this transformation. Here we report the iridium-catalyzed borylation of methane using bis(pinacolborane) in cyclohexane solvent. Initially, trace amounts of borylated products were detected with phenanthroline-coordinated Ir complexes.

Partial hydrogenation of a tetranuclear titanium nitrido complex with ammonia borane.

The treatment of [{Ti(η(5)-C5Me5)}4(μ3-N)4] with NH3BH3 leads to the paramagnetic imidonitrido complex [{Ti(η(5)-C5Me5)}4(μ3-N)3(μ3-NH)], which can also be obtained by stepwise proton and electron transfer with HOTf and [K(C5Me5)].

Reactivity with electrophiles of imido groups supported on trinuclear titanium systems.

Several trinuclear titanium complexes bearing amido μ-NHR, imido μ-NR, and nitrido μn-N ligands have been prepared by reaction of [{Ti(η(5)-C5Me5)(μ-NH)}3(μ3-N)] (1) with 1 equiv of electrophilic reagents ROTf (R = H, Me, SiMe3; OTf = OSO2CF3). Treatment of 1 with triflic acid or methyl triflate in toluene at room temperature affords the precipitation of compounds [Ti3(η(5)-C5Me5)3(μ3-N)(μ-NH)2(μ-NH2)(OTf)] (2) or [Ti3(η(5)-C5Me5)3(μ3-N)(μ-NH)(μ-NH2)(μ-NMe)(OTf)] (3). Complexes 2 and 3 exhibit a fluxional behavior in solution consisting of proton exchange between μ-NH2 and μ-NH groups, assisted by the triflato ligand, as could be inferred from a dynamic NMR spectroscopy study.

Electrophilic attack on trinuclear titanium imido-nitrido systems.

Alkylation of [{Ti(η(5)-C(5)Me(5))(μ-NH)}(3)(μ(3)-N)] with MeOTf occurs at the imido ligands to produce the methylamido derivative [Ti(3)(η(5)-C(5)Me(5))(3)(μ(3)-N)(μ-NH)(2)(μ-NHMe)(OTf)] which readily rearranges to form the methylimido complex [Ti(3)(η(5)-C(5)Me(5))(3)(μ(3)-N)(μ-NH)(μ-NH(2))(μ-NMe)(OTf)].