The Chemistry of Aluminum–nitrogen Compounds: Ii. Reactions of Tetramethyltetrazene With Aluminum Hydride and Trialkylaluminum Complexes

Abstract

The reaction of tetramethyltetrazene with MeaAl:NMer, Et3A1, and H3AI:NMe3 has let1 to a new method for the preparation of (hIe?AI-NMe2)?, (EtzAl-NMez)?, and EIzAI-X"JMe2, respectively. The reaction of tetramethyltetraze~le with Me3AI has produced AI(NMe2)3, MeAI(NMe2)2, and Me2AI-NMe?, and with Et3Al:NMea has produced Et3AI:Me?NN= NNMe2, EtzAI-NMe2, and the polymer (-AlEtNEt-) ,,. 111 all but one case, the complexes are formed by the interaction of a dimethylamine radical, which results from the cleavage of Me?NN=NNRle?, with the alu~ninum moiety and the subsequent elimination of an allianc or hydrogen.Recently (1) we reported the reactions of several niethylhydraziiies with trimethylaluminum. As a continuation of this preparative survey on compounds with covalent aluminum-nitrogen bonds, we have found an interesting cleavage of tetramethyltetrazelle (hereafter abbreviated as T M T ) during its reaction with aluminum hydride trimethylamine, aluminum alkyls, and trialkylaluminum trimethylamine complexes.The tetra-substituted tetrazenes exhibit thermal instability when heated in inert solvents, and they decompose t o form tetra-substituted hydrazines and nitrogen (2) :However, when T M T is treated with aluminum hydride trimethylami~ie, the dimethylamino groups do not combine, but react, with the aluminum-hydrogen bond to form H2Al-NMe2 plus hydrogen, nitrogen, and trimethylamine:Me2KN=NNNIe? + 2H3Al:Ni\le3 + 2EI?.qI--NMe? + 2NRle3 + N? + I-I?.T h e reactions of TRilT with trimethylaluininu~n and trietl~ylalurnin~~~n proceed in a similar manner. However, in several cases more than one alkyl group on aluminum was replaced by a dimethylamino group; thus, in the reaction of MeaAl with T M T , we obtained (Me2Al-NRile2)2, MeAl(NMez)n, and A1(NMe2)3. i l p p a r a t~~s and Starting illaterialsAll the work described here mas carried out with the aid of a conventional high-vacu~un system. Infrared spectra were talten employing a Model IR-5 Beclcman infrared spectrophotometer with sodium chloride optics. The spectra of gases were taken i11 a 10-c~n cell equipped with KaCI windows, and the spectra oi liquids were talren in a NaCl cell with a 0.001-inch lead spacer. Molecular weights were dctermined cryoscopically in an all-glass apparatust which could be filled in an inert atmosphere chamber.: The q o l v e~l~ used was Fisher certified reagent grade cyclohexane.

Some Reactions of Organoaluminum Compounds With Nitrogen-Containing Bases

“…The apparatus and procedures employed have been described previously (1,4). The arni~les and hydrazines were distilled fro111 CaH?…”

Addition of complexed amino radicals to conjugated alkenes

“…The initially formed material was purified by LC and then recrystallized from pentane, mp 33-34 °C (lit.12 34 °C). NMR spectrum (CDC13): 2.09 (m, 3 H, a-CH3), 3.66, (s, 3 H, methoxyl), 4.96 (m, 1 H, olefinic CH), 5.30 (m, 1 H, olefinic CH), 7.08 (A2B2, 4 H, aromatic). p-Bromo-a-methylstyrene was made in 77% yield from p-bromoacetophenone.…”

“…The material had bp 82-83 °C (20 mm) [lit.13 69 °C (10 mm)] and was pure by GLPC and NMR standards. NMR spectrum (CDCI3): 2.05 (m, 3 H, a-CH3), 2.25 (s, 3 H,p-CH3), 5.00 (m, 1 H, olefinic CH), 5.33 (m, 1 H, olefinic CH), 7.15 (A2B2, 4 H, aromatic).…”

THE CHEMISTRY OF ALUMINUM–NITROGEN COMPOUNDS: IV. THE REACTIONS OF Me3Al AND H3Al:NMe3 WITH SEVERAL TERTIARY POLYAMINES

“…The experimental apparatus and procedures have been described in earlier publications (2,3). The Me2N(CH2)3NMe2 and the i\le2NCHpCH=CHCH2Ni\le2 were supplied by the Ames Laboratories of Milford, Conn., and were used without further purification.…”