Redox-Active Behavior of the [{Ti(η5‑C5Me5)(μ-NH)}3(μ3‑N)] Metalloligand

Treatment of [Cl3Y­{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] with [K­(C5Me5)] in toluene gives C10Me10 and the paramagnetic [K­(μ-Cl)3Y­{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (3) derivative. Crystallization of 3 in pyridine affords the potassium-free [Cl2(py)2Y­{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (4) complex. Whereas the reaction of 3 with 1 equiv of 18-crown-6 leads to the molecular complex [(18-crown-6)­K­(μ-Cl)3Y­{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (5), the analogous treatment of 3 with cryptand-222 affords the ion pair [K­(crypt-222)]­[Cl3Y­{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (6). The X-ray crystal structures of 4, 5, and 6 have been determined. Density functional theory (DFT) calculations have elucidated the electronic structure of these species, which should be regarded as containing trivalent Y bonded to the {(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)} metalloligand radical anion.