Synthesis, Structures, Photoluminescent Behaviors, and DFT Studies of Novel Aluminum Complexes Containing Phenoxybenzotriazole Derivatives

Treatment of AlMe3 with 2 equiv of 2-(2H-benzo[d][1,2,3]triazol-2-yl)-4,6-di-tert-pentylphenol (Lig1H) or 2-tert-butyl-6-(5-chloro-2H-benzo[d][1,2,3] triazol-2-yl)-4-methylphenol (Lig2H) and subsequent addition of ROH afford monomeric and heteroleptic (OR)AlL2 complexes [R = C6H5, L = Lig1, 1; R = p-C6H4Ph, L = Lig1, 2; R = C6H5, L = Lig2, 3; R = p-C6H4Ph, L = Lig2, 4]. The simple reaction between a quantitative amount of water and compound 1 gave the novel dimeric aluminum complex 5 bridged by an oxygen atom. The crystal structures of 1, 3, and 5 determined from X-ray diffraction studies reveal pentacoordination geometry around the Al center with the preference for the slightly distorted trigonal-bipyramidal geometry. Monomeric complexes 1−4 showed emissions of the blue region (475 nm) with broad emission areas (half-width of peak = 150 nm) in the emission spectrum with high quantum yield. Dimeric aluminum complex 5 with enhanced thermal stability has a similar absorption and emission pattern to complexe...