[Characterization and photoluminescence properties of a blue-light-emitting material].

Tris (2-methyl-8-hydroxyquinoline) aluminum (AlMeq3) was synthesized and purified by vacuum sublimation. The structure of the complex was characterized by 1H NMR, FTIR spectra and elemental analysis techniques. AlMeq3 consists of three 2-methyl-8-hydroxyquinoline ligands and one aluminum atom. Its thermal stability was studied by TG and DSC analysis and the result shows that AlMeq3 is a thermally stable material, with decomposition and crystalline transition temperature being 357 and 158 degrees C, respectively. Energy band structure was investigated by UV-Vis absorption spectra and fluorescence emission spectra. Experimental results show that its UV absorption bands were at about 246 and 390 nm, and the absorption band at about 246 nm can be assigned to pi--pi* of phenyl ring. AlMeq2 displays 8-hydroxyquinoline-oriented photophysical properties. The optical gap of AlMeq3: was about 2.85 eV, as determined by intrinsic absorption band edge of the complex in ethanol solution. Under UV excitation at 365 nm, the complex in ethanol solution emitted intensive blue fluorescence with the maximum emission peak at 479 nm, while the effective energy-transfer from the ligand to the central AlP+ ion occurred in the complex. AlMeq3 with bright blue photoluminescence can be applied as luminescent material in OLEDs.