Heterometallic complexes with cube-type [MTi3N4] cores containing Group 10 metals in a variety of oxidation states.

Abstract

Treatment of [{Ti(η5-C5Me5)(μ-NH)}3(μ3-N)] (1) with one equivalent of [Ni(cod)2] (cod = 1,5-cyclooctadiene) in toluene at 60–80 °C and subsequent addition of diphenylacetylene, trans-stilbene or triphenylphosphane afforded the nickel(0) complexes [LNi{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (L = PhCCPh (2), PhCH≡CHPh (3), PPh3 (4)). The nickel(II) complex [I2Ni{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (5) was prepared by analogous addition of iodine to the solution obtained from the heating of 1 and [Ni(cod)2]. Treatment of 1 with one equivalent of [Pd(dba)2] (dba = dibenzylideneacetone) in toluene at room temperature led to the palladium(0) complex [(dba)Pd{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (6). Compound 6 reacted immediately with chloroform-d1 to give the palladium dichloride derivative [Cl2Pd{(μ3-NH)2Ti3(η5-C5Me5)3(μ-NH)(μ3-N)}] (7), which was prepared by treatment of 1 with [PdCl2(cod)] at room temperature. Addition of iodine to a toluene solution of 6 afforded the analogous palladium(II) derivative [I2Pd{(μ3-NH)2Ti3(η5-C5Me5)3(μ-NH)(μ3-N)}] (8). Complex 6 reacted with two equivalents of dimethylacetylenedicarboxylate (dmad) to give the metallacyclopentadiene palladium(II) complex [{(MeOOC)4C4}Pd{(μ3-NH)2Ti3(η5-C5Me5)3(μ-NH)(μ3-N)}] (9) via oxidative coupling. The treatment of 1 with [Pt(nbe)3] (nbe = norbornene) in toluene at room temperature gave the platinum(0) complex [(nbe)Pt{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (10). Compound 10 reacted with excess iodine to afford the platinum(IV) ionic derivative [I3Pt{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}]2(I3)(I5) (11) via an intermediate platinum(II) complex [I2Pt{(μ3-NH)2Ti3(η5-C5Me5)3(μ-NH)(μ3-N)}] (12). The X-ray crystal structures of 5, 8, 9 and 11 have been determined.