Cyclopentadienyl and Alkynyl Copper(I) Derivatives with the [{Ti(η5-C5Me5)(μ-NH)}3(μ3-N)] Metalloligand

Abstract

The treatment of [ClCu{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (2) with lithium cyclopentadienide in toluene at room temperature affords [(C5H5)Cu{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (4), where the cyclopentadienyl ligand is bound to copper(I) in an η2 fashion. The analogous reaction of 2 with lithium acetylides [Li(C≡CR)] gives complexes [(RC≡C)Cu{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (R = SiMe3 (5), Ph (6)) with terminal alkynyl ligands bound to copper. Compound 6 is prepared in higher yield by the treatment of [{Ti(η5-C5Me5)(μ-NH)}3(μ3-N)] (1) with [Cu(C≡CPh)] in toluene at room temperature. The cyclopentadienyl derivative 4 decomposes in solution to generate the edge-linked double-cube nitrido complex [{Cu(μ4-N)(μ3-NH)2Ti3(η5-C5Me5)3(μ3-N)}2] (3) via C5H6 elimination. However, solutions of the alkynyl derivatives 5 and 6 lead to copper(I) acetylide-bridged double-cube complexes [{Cu(μ-1κC1:2κC1-C≡CR)Cu(μ4-N)(μ3-NH)2Ti3(η5-C5Me5)3(μ3-N)}2] (R = SiMe3 (7), Ph (8)) along with 1 and RC≡CH. The X-ray crystal structures of 4, 5, 7, and 8 have been determined.