Die Umsetzung von Dialkylaluminiumchloriden mit Bis(trimethylsilyl)hydrazin: Bildung von Addukten R2AlCl · NH2NHSiMe3 mit dem thermisch unbeständigen Trimethylsilylhydrazin

Self Cite

Treatment of the hydrazine adduct (Me3C)2AlCl·NH2NHSiMe3 (2) with n‐butyllithium afforded the colorless dialkylaluminium hydrazide (Me3C)2AlN(SiMe3)NH2 (3) by the release of butane and the precipitation of LiCl. Hydrazide 3 gave a dimer in solution and in the solid state. As shown by a crystal structure determination, a six‐membered Al2N4 heterocycle with two intact endocyclic N−N bonds was formed by a head‐to‐tail dimerization. Upon sublimation of 3 in vacuum, a rearrangement was observed which gave an isomeric compound 4 after the migration of a hydrogen atom of a hydrazido ligand. The molecular core of 4 comprises a five‐membered Al2N3 heterocycle, in which the Al atoms are bridged by one hydrazido ligand similar to 3. The second ligand, however, has only one nitrogen atom in a bridging position with an exocyclic N−N bond. A similar compound (5) was obtained by the reaction of bis(tert‐butyl)aluminium chloride with phenylhydrazine and n‐butyllithium.

“…[10] As is reported here, these adducts are excellent starting materials for the synthesis of aluminium hydrazides under mild conditions. Scheme 1 …”

Section: Introductionmentioning

confidence: 57%

Section: Quantum Mechanical Calculationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Aluminium Hydrazides: Dimeric Bis(tert-butyl)aluminium Hydrazides withSix-Membered Al2N4 and Five-Membered Al2N3 Heterocycles

Uhl

Molter

Koch

2000

Self Cite

“…[14] Moreover, Uhl et al found that the reaction of tBu 2 AlCl with H 2 NNHSiMe 3 produced tBuCl 2 -Al·NH 2 ϪNHSiMe 3 , a compound that is analogous to compound 1. [61] It is interesting that the tert-butylhydrazine removes MeGaCl 2 from the equilibrium in Equation (1) while the lithium hydrazide Li(Me 3 Si)NϪNHϪtBu adds to trimethylgallium and not to a methylgallium chloride molecule. This can be rationalized as follows.…”

Section: Discussionmentioning

confidence: 99%

“…This compound was isolated and fully characterized. Nevertheless, it is once again an unexpected product, as shown in Equation (10). Compound 9 can be regarded as the adduct of a bis(dimethylindium) oxide (diindoxane) with lithium tris(trimethylsilyl)hydrazide.…”

Section: Synthesismentioning

confidence: 99%

Hydrazino Derivatives of Gallanes and Indanes − Synthesis and Structures

Nöth

Seifert

2002

The reaction of Me2GaCl with tBuHN−NH2 proceeds with ligand exchange at the gallium atom leading to MeCl2Ga·H2N−NHtBu (1). On the other hand, only one methyl group of the trimethylgallium molecule reacts in refluxing toluene with anhydrous hydrazine in a 4:3 ratio to produce the bicyclic dimethylgallium hydrazide 3. N‐Lithio‐N‐trimethylsilyl‐N′‐2‐naphthylhydrazine reacts with dimethylgallium chloride, not only by introducing a gallium atom into the hydrazine unit, but also by inducing CH activation at the 1‐position of the naphthyl group with methane evolution. The main product isolated is the 2,3‐dihydro‐1H‐naphtho[1,2‐d][1,2,3]diazagallol 4 which proved to be dimeric. A 1:1 GaMe3 adduct of Li(Me3Si)N−NHtBu (5) is the unexpected compound in the reaction of Me2GaCl with Li(Me3Si)N−NHtBu. The expected substitution product Me2Ga(Me3Si)N−NHtBu is not formed. Compound 5 is a dimer in the solid state. The products obtained from reactions of Li(Me3Si)N−NHtBu with Me2InCl depend on the solvent. With hexane as a solvent the dimeric trimethylindium adduct of Li(Me3Si)N−NHtBu (7), is produced as the main species. In diethyl ether the cage compound 8 is isolated which can be regarded as an (Me3SiN=InMe)2 adduct with [Li(Me3Si)N−NHtBu]2. Moreover, the reaction of Me2InCl in diethyl ether with the bulky lithium hydrazide Li[Me3SiN−N(SiMe3)2] leads not to the substitution product, but to the dimeric adduct 9 of a diindoxane, Me2In−O−InMe2 with Li(Me3Si)N−N(SiMe3)2. The formation of this product indicates that ether cleavage or hydrolysis (during crystallization) has occurred.

Aluminium Hydrazides: Reactions oftert-Butylaluminium Chlorides with Dilithium Bis(trimethylsilyl)hydrazide – Formation of Iminoalanes and their Hydrazido Adducts

Uhl¹,

Molter

Koch

1999

Di(tert‐butyl)aluminium chloride reacted with dilithium bis(trimethylsilyl)hydrazide with the formation of a novel Al2Li2N4 cage compound 1. Its structure consists of a dimeric iminoalane RAl(μN–SiMe3)2AlR (R = CMe3), which is bridged by a dilithiumhydrazido ligand with an intact N–N bond. A heterocubane‐type molecule is formed, in which two vertices are occupied by Al atoms, two by Li atoms and four by N atoms. One face of the cube is strongly distorted due to the short N–N distance of the hydrazido group. A similar compound, 3, was formed with bis(neopentyl)aluminium chloride but it was isolated in very poor yield. The reaction of Li2N2(SiMe3)2 with (Me3C)2AlCl in the presence of THF yielded an adduct 2, in which each Li atom of the cage is additionally coordinated via Li–Cl–Al bridges to the ligand (Me3Al)2Cl·THF. The reaction of dilithium bis(trimethylsilyl)hydrazide with tert‐butylaluminium dichloride gave, by complete cleavage of the hydrazido groups, a dimeric iminoalane [Me3C(THF)AlNSiMe3]2 (4), in which each aluminium atom is coordinated to one THF molecule. Its uncoordinated, solvent‐free form 5 was obtained by heating solid 4 to 150 °C in vacuo for several hours. It was identified as the tetrameric iminoalane (Me3CAlNSiMe3)4, which does not adopt the expected heterocubane‐type structure, but consists of three anellated four‐membered Al2N2 heterocycles in a kind of ladder structure. Remarkably, the cage compound 1 could not be obtained by the reaction of an excess of lithium hydrazide with the iminoalanes 4 and 5. All compounds 1–5 were characterized by crystal structure determinations.