Tetramethylpiperidine–Alane Adducts tmpH · AlX3 (X = Cl, Br, I) and tmpH · AlH2Cl: Synthesis, Solution Behavior, and X-ray Crystal Structures☆

✍ Scribed by Ingo Krossing; Heinrich Nöth; Holger Schwenk-Kircher; Thomas Seifert; Christiane Tacke

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 159 KB
• Volume: 1998
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/(sici)1099-0682(199812)1998:12<1925::aid-ejic1925>3.0.co;2-u

✦ Synopsis

Conductivity measurements / 27 Al-NMR spectroscopy 2,2,6,6-Tetramethylpiperidine (tmpH) reacts smoothly with • AlX 3 (X = Cl, Br, I) and tmpH • AlH 2 Cl are tetracoordinated molecular adducts. While this is also true for solutions of aluminum trihalides AlX 3 (X = Cl, Br, I) and monochloroalane AlH 2 Cl • 2 thf to give the addition compounds tmpH • AlX 3 tmpH • AlX 3 (X = Br, I) and tmpH • AlH 2 Cl, the compound tmpH • AlCl 3 dissolves in CH 2 Cl 2 as the salt [tmpAlCl 3 ]-(X = Cl, Br, I) and tmpH • AlH 2 Cl, respectively. These adducts of the secondary amine tmpH are stable and do not undergo tmpH 2 and the adduct tmpH • Al 2 Cl 6 , as is evident from its NMR spectra and from conductivity measurements. This intramolecular elimination of HX or H 2 with formation of the aminoalanes tmpAlX 2 or tmpAl(H)Cl. In the solid state, tmpH behavior is supported by a semiempirical AM1 calculation.