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), PhCHCHPh (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.