Cadmium and mercury complexes containing trinuclear titanium imido-nitrido metalloligands

Abstract

Several heterometallic nitrido complexes have been prepared from the reaction of the trinuclear imido-nitrido titanium complex [{Ti(5-C5Me5)(mu-NH)}3(mu 3-N)] (1) with cadmium and mercury derivatives. Treatment of 1 with cadmium dichloride or cadmium diiodide in toluene afforded the adducts [X2Cd{(mu 3-NH)3Ti3(5-C5Me5)3(mu 3-N)}] [X = Cl (2), I (3)]. Complex 2 reacted with lithium reagents [LiR] in toluene to give the cube-type derivatives [RCd{(mu 3-N)(mu 3-NH)2Ti3(5-C5Me5)3(mu 3-N)}] [R = CH2SiMe3 (4), C=CSiMe3 (5), C5H4(SiMe3) (6), N(SiMe3)2 (7)]. The amido complex 7 reacted with 1 equiv. of 1 to give the corner-shared double-cube complex [Cd{(mu 3-N)(mu 3-NH)2Ti3(5-C5Me5)3(rho 3-N)}2] (8) by means of bis(trimethylsilyl)amine elimination. Treatment of 1 with mercury(II) iodide in toluene gave the adduct [I2Hg{(mu 3-NH)3Ti3(5-C5Me5)3(mu 3-N)}] (9), which reacted with [K{N(SiMe3)2}] to afford [Hg{(mu 3-N)2Ti3(5-C5Me5)3(mu-NH)(mu 3-N)}]2 (10) through the amido mercury intermediate [{(Me3Si)2N}Hg{(mu 3-N)Ti3(5-C5Me5)3(mu-NH)2(mu 3-N)}] (11). Compound 11 and the analogous alkyl derivative [(Me3SiCH2)Hg{(mu 3-N)Ti3(5-C5Me5)3(mu-NH)2(mu 3-N)}] (12) were characterised by NMR spectroscopy upon the treatment of 1 with [Hg{N(SiMe3)2}R] [R = N(SiMe3)2, CH2SiMe3]. Complex [Hg{(mu 3-N)Ti3(5-C5Me5)3(mu-NH)2(mu 3-N)}2] (13), with one bridging mercury atom between two titanium trinuclear systems, was obtained upon treatment of HgI2 with the potassium derivative [K(mu 4-N)(mu 3-NH)2{Ti3(5-C5Me5)3(mu 3-N)}]2. Complexes 3, 5 and 8 were characterised by single-crystal X-ray diffraction analysis.