811470-67-4Relevant academic research and scientific papers
Aluminium alkyl and aryloxide complexes of pyrazine and bipyridines: Synthesis and structure
Ogrin, Doug,Van Poppel, Laura H.,Bott, Simon G.,Barron, Andrew R.
, p. 3689 - 3694 (2004)
The reaction of AlMe3 and [(tBu)2Al(μ- OPh)]2 with pyrazine (pyz), 4,4′-bipyridine (4-4′-bipy), 1,2-bis(4-pyridyl)ethane (bpetha) and 1,2-bis(4-pyridyl)ethylene (bpethe) yields (Me3Al)2(μ-pyz) (1), (Me3Al) 2(μ-4,4′-bipy) (2), (Me3Al)2(μ- bpetha) (3), (Me3Al)2(μ-bipethe) (4), Al( tBu)2(OPh)(pyz) (5), [(tBu)2Al(OPh)] 2(μ-4,4-bipy) (6a), [(tBu)2Al(OPh)] 2(μ-bpetha) (7a), [(tBu)2Al(OPh)] 2(μ-bipethe) (8a). Compounds 1-4, 6a and 7a have been confirmed by X-ray crystallography. In solution compounds 1-4 undergo a rapid ligand-dissociation equilibrium resulting in a time-average spectrum in the 1H NMR. In contrast, the solution equilibria for compounds 5-8a are sufficiently slow such that the mono-aluminium compounds may be observed by 1H NMR spectroscopy: Al(tBu)2(OPh)(4,4-bipy) (6b), Al(tBu)2(OPh)(bpetha) (7b) and Al( tBu)2(OPh)(bpethe) (8b). The inability to isolate [( tBu)2Al(OPh)]2(μ-pyz) and the relative stability of each complex is discussed with respect to the steric interactions across the bridging ligand (L) and the electronic effect on one Lewis acid-base interaction by the second Lewis acid-base interaction on the same ligand.
