Heterometallic Cube-Type Molecular Nitrides

A wide family of heterometallic nitrido complexes with [MTi3N4] cube-type cores has been prepared by incorporation of most of the metallic elements of the Periodic Table into the incomplete cube structure of [{TiCp*(μ-NH)}3(μ3-N)] (Cp* = η5-C5Me5).Ministerio de Economía y Competitividad de España, Comunidad de Madrid, Universidad de Alcal

Amido-bridged double cube nitrido complexes containing titanium and magnesium/calcium

Treatment of the single cube nitrido complexes [(thf)(x){(Me3Si)(2)N} M{(mu(3)-N)(mu(3)-NH)(2)Ti-3(eta(5)-C5Me5)(3)(mu(3)-N)}] (M = Mg, x = 0; Ca, x = 1) with one equivalent of anilines NH2Ar in toluene affords the arylamido complexes [(ArHN) M{(mu(3)-N)(mu(3)- NH)(2)Ti-3(eta(5)-C5Me5)(3)(mu(3)-N)}](n) [M = Mg ( 3), n = 1, Ar = 4-MeC6H4; Ca (4), n = 2, Ar = 2,4,6-Me3C6H2]. The magnesium complex 3 has a single-cube structure whereas the X-ray crystal structure of the analogous calcium derivative 4 shows two cube-type azaheterometallocubane moieties "Ca{(mu(3)-N)(mu(3)- NH)(2)Ti-3(eta(C5Me5)-C-5) (3)(mu(3)-N)}" held together by two mu-2,4,6-trimethylanilido ligands. Complexes 3 and 4 react with chloroform-d(1) at room temperature to give the metal halide adducts [Cl2M{(mu(3)-NH)(3)Ti-3(eta(5)-C5Me5)(3)(mu(3)- N)}] (M = Mg, Ca). A solution of 3 in n-hexane gave complex [{Mg-2(mu(3)-N)(mu(3)-NH)(5)[ Ti-3(eta(5)- C5Me5)(3)(mu(3)- N)](2)}(mu-NHAr)(3)] which shows three mu-4-methylanilido ligands bridging two [MgTi3N4] cube type cores according to an X-ray crystal structure determination.Ministerio de Ciencia y Tecnología, Comunidad de Madri

X-Ray Crystal Structures of Two Monopentamethylcyclopentadienylhafnium(IV) Complexes

The crystal structures of two monopentamethylcyclopentadienyl-hafnium(IV) derivatives have been determined by X-ray diffraction analysis. The [Hf(eta5-C5Me5)Cl3] complex (I) crystallizes as a dimer in the monoclinic space group C2/c with Z = 8. The structure of I is described as two {Hf(eta5-C5Me5)Cl2} units linked by two bridging chloride ligands. The [{Hf(eta5-C5Me5)Cl}3(mu-Cl)4(mu3-O)] complex (II) crystallizes in the monoclinic space group Cc with Z = 4. The structure of II is described as three {Hf(eta5-C5Me5)Cl} moieties connected by one or two bridging mu-chloride ligands and an additional mu3-oxide group. The hitherto unknown compound II has also been characterized by spectroscopic and analytical methods. In the solid state, the molecules of both derivatives are linked by C-H···Cl hydrogen bonds and C-H···pi interactions, providing an alternating layered pattern.Universidad de Alcal

Cleavage of Dinitrogen from Forming Gas by a Titanium Molecular System under Ambient Conditions

Simple exposure of a hexane solution of [TiCp*Me3](Cp* = h5-C5Me5) to an atmosphere of commercially available and inexpensive forming gas (H2/N2 mixture, 13.5-16.5 % of H2) at room temperature leads to the methylidene-methylidyne-nitrido cube-type complex [(TiCp*)4(m3-CH)(m3-CH2)(m3-N)2] via dinitrogen cleavage. This paramagnetic compound reacts with [D1]chloroform to give the titanium(IV) methylidyne-nitrido species [(TiCp*)4(m3-CH)2(m3-N)2], whereas its one-electron oxidation with AgOTf or [Fe(h5-C5H5)2](OTf) (OTf = O3SCF3) yields the diamagnetic ionic derivative [(TiCp*)4(m3-CH)(m3-CH2)(m3-N)2](OTf). The m3-nitrido ligands of the methylidyne-nitridocubane complex can be protonated with [LutH](OTf)(Lut = 2,6-lutidine) or hydrogenated with NH3·BH3 to afford m3-NH imido moieties.Ministerio de Economía y Competitividad de España, Universidad de Alcal

Cube-Type Nitrido Complexes Containing Titanium and Alkali/Alkaline-Earth Metals

(M = Ca, Sr) have been determined. The properties and solid-state structures of the azaheterometallocubane complexes bearing alkali and alkaline-earth metals are discussed.Ministerio de Ciencia y Tecnología de España, Comunidad de Madrid, Universidad de Alcal

Cadmium and mercury complexes containing trinuclear titanium imido-nitrido metalloligands

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.Ministerio de Educación y Ciencia de Españ

Isolable zirconium hydride species in the reaction of amido complexes with amine-boranes

Mono-, di- and trinuclear zirconium hydride species have been isolated in the treatment of amido complexes [Zr(η5-C5Me5)(NMe2)nCl3-n] (n = 3, 1) with amine‒borane adducts NHR2BH3 (R2 = Me2, HtBu). The reactions involve the formation of amidoborane ligands with Zr···H-B interactions which readily undergo β-hydride elimination to give hydride functions.Ministerio de Economía y Competitividad de España, Universidad de Alcal

Cyclopentadienyl yttrium complexes with the [{Ti(η5-C5Me5)(μ-NH)}3(μ3-N)] metalloligand

The reactivity of the yttrium trichloride complex [Cl3Y{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (2) with a variety of main-group metal cyclopentadienyl reagents [M(C5H3R1R2)] (M = Li, Na, K, Tl) or [Mg(C5H5)2] has been investigated. Treatment of 2 with one equivalent of [Na(C5H5)] or [K(C5H4SiMe3)] gives the monocyclopentadienyl derivatives [(η5-C5H4R)Cl2Y{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (R = H (3), SiMe3 (4)). Analogous reaction of 2 with lithium [Li(C5H3R1R2)] or thallium [Tl(C5H5)] reagents (1 or 2 equivalents) leads to complexes [(η5-C5H3R1R2)2Y(μ-Cl)2M{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}] (M = Li, R1 = R2 = H (5), R1 = H, R2 = SiMe3 (6), R1 = R2 = SiMe3 (7); M = Tl, R1 = R2 = H (8)). Complex 2 reacts with [Mg(C5H5)2] to yield the ionic compound [(μ-Cl)3Mg2{(μ3-NH)3Ti3(η5-C5Me5)3(μ3-N)}2][{Y(η5-C5H5)2Cl}2(μ-Cl)] (9). In contrast to the metathesis of chloride ligands, the reaction of 2 with the lithium indenyl derivative [Li(C9H7)] at room temperature produces C9H8 and the precipitation of [Li(μ-Cl)3Y{(μ3-N)(μ3-NH)2Ti3(η5-C5Me5)3(μ3-N)}] (10). Crystallization of 10 in pyridine affords the lithium-free [Cl2(py)2Y{(μ3-N)(μ3-NH)2Ti3(η5-C5Me5)3(μ3-N)}] (11) complex. The X-ray crystal structures of 6 and 11 have been determined.Ministerio de Economía y Competitividad de España, Universidad de Alcal