Cube-Type Nitrido Complexes Containing Titanium and Zinc/Copper

Abstract

Several azaheterometallocubane complexes containing [MTi3N4] cores have been prepared by the reaction of [{Ti(eta(C5Me5)-C-5)( mu-NH)}(3)(mu(3)-N)] (1) with zinc(II) and copper(I) derivatives. The treatment of 1 with zinc dichloride in toluene at room temperature produces the adduct [Cl2Zn {(mu(3)-NH)(3)Ti-3(eta(5)-C5Me5)(3)(mu(3)-N)}] (2). Attempts to crystallize 2 in dichloromethane gave yellow crystals of the ammonia adduct [(H3N) Cl2Zn {(mu(3)-NH) Ti-3(eta(5)-C5Me5)(3)(mu-NH)(2)(mu(3)- N)}] ( 3). The analogous reaction of 1 with alkyl, ( trimethylsilyl) cyclopentadienyl, or amido zinc complexes [ ZnR2] leads to the cube-type derivatives [RZn {(A(3)-N)(mu(3)-NH)(2)Ti-3(eta(5)-C5Me5)(3)(mu(3)-N)}] (R) CH2SiMe3 (5), CH2Ph (6), Me ( 7), C5H4SiMe3 (8), N(SiMe3)(2) (9)) via RH elimination. The amido complex 9 decomposes in the presence of ambient light to generate the alkyl derivative [{Me3Si(H) N(Me) 2SiCH2} Zn {(mu(3)-N)(mu(3)-NH)(2)Ti-3(eta(5)-C5Me5)(3)(mu(3)-N)}] (10). The chloride complex 2 reacts with lithium cyclopentadienyl or lithium indenyl reagents to give the cyclopentadienyl or indenyl zinc derivatives [RZn {(mu(3)-N)(mu(3)-NH)(2)Ti-3(eta(5)-C5Me5)(3)(mu(3)-N)}] (R) C5H5 (11), C9H7 (12)). Treatment of 1 with copper(1) halides in toluene at room temperature leads to the adducts [XCu {(mu(3)-NH)(3)Ti-3(eta(5)-C5Me5)(3)(mu(3)-N)}] ( X) Cl ( 13), I (14)). Complex 13 reacts with lithium bis( trimethylsilyl) amido in toluene to give the precipitation of [{Cu(mu(4)-N)(mu(3)- NH)(2)Ti-3(eta(5)-C5Me5)(3)(mu(3)- N)}(2)] (15). Complex 15 is prepared in a higher yield through the reaction of 1 with [{CuN(SiMe3)(2)}(4)] in toluene at 150 degrees C. The addition of triphenylphosphane to 15 in toluene produces the single-cube compound [( Ph3P) Cu {(mu(3)-N)(mu(3)-NH)(2)Ti-3(eta(5)-C5Me5)(3)(mu(3)-N)}] (16). The X-ray crystal structures of 3, 8, 9, and 15 have been determined.