Synthesis, characterization and photoluminescence of aluminum N-aryloxo functionalized β-ketoiminate complexes

The synthesis, characterization and luminescent properties of aluminum complexes containing a dianionic N-aryloxo functionalized beta-ketoiminate ligand are presented. 4-(2-Hydroxy-5-R-phenyl)imino-2-pentanone (R = Me, (LH2)-H-1; R = tert-butyl, (LH2)-H-2) ligands reacted with AlEt3 in tetrahydrofuran to give the aluminum complexes ((LAlEt)-Al-1)(2) (1) and ((LAlEt)-Al-2)(2) (2) in reasonable isolated yields. X-ray diffraction revealed that complexes 1 and 2 have solvent-free centrosymmetric dimeric structures, and each aluminum center has distorted trigonal bipyramidal geometry. At room temperature, complexes 1 and 2 exhibit blue photoluminescence in acetonitrile with maximum emission wavelengths of 419 and 413 nm, respectively.