Syntheses and Structural Characterization of a LAl(N₃)N[μ-Si(N₃)(tBu)]₂NAl(N₃)L and a Monomeric Aluminum Hydride Amide LAlH(NHAr) (L = HC[(CMe)(NAr)]₂, Ar = 2,6-iPr₂C₆H₃)

Abstract

Reactions between the aluminum(I) monomer LAl (L = HC[(CMe)(NAr)]2, Ar = 2,6-iPr2C6H3) and organic azides (RN3, R = C10H15 (adamantyl), Ph3Si; tBuSi(N3)3) are reported. LAl reacted with the bulky azide RN3 in toluene in a temperature range of −50 to 25 °C, resulting in the compound LAl[(NR)2N2] (R = C10H15 (1), Ph3Si (2)) instead of the expected AlN multiple bond species, while the reaction with tBuSi(N3)3 gave LAl(N3)N[(μ-Si(N3)(tBu)]2NAl(N3)L (3). Compounds 1−3 have been fully characterized by mass spectrometry and IR and multinuclear NMR spectroscopy (1H, 13C, and 29Si) as well as by single-crystal X-ray crystallography. The structural analysis of 1 and 2 reveals an AlN4 planar five-membered ring compound, suggesting a [2 + 3] cycloaddition of the AlN multiple bond species with a molecule of RN3 despite the steric bulk of the L and R substituents. Compound 3 shows a bonding of the N3 group to the Al and a formation of the N2Si2 central core, implying the migration of N3 and a [2 + 2] cycloaddition in the reaction sequence. In addition, the solvent-free reaction of an aluminum dihydride LAlH2 with ArNH2 was also investigated at elevated temperatures (150−290 °C), and a monomeric aluminum hydride amide, LAlH(NHAr) (4), was obtained as the only isolable product. The Al−H and N−H groups of 4 are shown in the IR and 1H NMR spectra. The corresponding X-ray structural analysis exhibits the Al−H and N−H bonds that are nearly arranged in position trans to the Al−NNHAr bond.

Synthesis, Characterization, and Reaction of Aluminum Halide Amides Supported by a Bulky β-Diketiminato Ligand

“…The Al-N(3) separation[1.8361(12) Å] is very close to those of [((Me 3 Si) 2 N) 2 Al(µ-CH 2 )]2 [1.832(3) and 1.837(3) Å] 29 while longer than those of Mes 2 AlN (SiMe 3 ) 2 [1.813(7)Å]8 and of the dimeric iminoalane[1.790 and 1.818. Å] containing three-coordinate Al centers 30 and shorter than that of [(Me 3 Si) 2 N] 2 AlH 2 Li · 2Et 2 O (av 1.862 Å) with the four-coordinate Al center.17 The Al-N(1) and Al-N(2) bond lengths (1.891-1.929 Å) in 1-3 are close to the ones reported9,22,28,31 and obviously longer than the Al-N(3) distances (1.788-1.836 (26) Brothers, P. J.; Wehmschulte, R. J.; Olmstead, M. M.; Ruhlandt-Senge, K.; Parkin, S. R.; Power, P. P. Organometallics 1994, 13, 2792-2799. (27) Leggett, G.; Motevalli, M.; Sullivan, A. C. J. Organomet.…”

“…2 Oligomeric nitrogen-rich compounds 3,4 or structurally characterized monomers [5][6][7][8][9] have been developed for this purpose. There are, however, only a few examples known of monomeric aluminum halide amides with two different substituents.…”

Reduction of organic azides by indyl-anions. Isolation and reactivity studies of indium–nitrogen multiple bonds

“…It is of note that, if insufficient steric protection is provided during synthesis, in situ addition of unreacted azide in the reaction mixture to the transient ‘MNR’ bonds can occur (Scheme 1). 17 For Al and Ga, this has enabled the isolation of metallotetrazenes VII (also referred to as metal-containing tetrazoles),17,18 which are rationalized as the product of a (2 + 3)-cycloaddition. This chemistry has not been extended to indium.…”

Yttrium-catalysed dehydrocoupling of alanes with amines

“…For example, complex 4g has been previously reported by H. Roesky and co-workers and may be synthesized by the thermolysis of 1b in neat 2,6-di-isopropylaniline at 150 o C for 1h. Conducting this reaction in a flame-sealed NMR tube in toluene-d 8 gave only trace conversion after 1d at 150 o C. 13 diethyl ether (2 mL) was added followed by addition of the amine (0.33 mmol). Vigorous effervescence was observed and the vial was sealed.…”