Dialkylaluminum Complexes with Chelating Anilido-Imine Ligands: Synthesis, Structures, and Luminescent Properties

Syntheses of three new chelating anilido-imine conjugated ligands, ortho-C6H4(NHAr‘)(CHNAr‘ ‘) [Ar‘ = Ar‘ ‘ = 2,6-Me2C6H3 (2b); Ar‘ = p-MeC6H4, Ar‘ ‘ = 2,6-iPr2C6H3 (2c); Ar‘ =
Ar‘ ‘ = p-MeC6H4 (2d)], as well as their four-coordinate dialkyl aluminum complexes, ortho-C6H4(NAr‘)(CHNAr‘ ‘)AlMe2 [Ar‘ = Ar‘ ‘ = 2,6-iPr2C6H3 (3a); Ar‘ = Ar‘ ‘ = 2,6-Me2C6H3 (3b);
Ar‘ = p-MeC6H4, Ar‘ ‘ = 2,6-iPr2C6H3 (3c); Ar‘ = Ar‘ ‘ = p-MeC6H4 (3d)], are described.
Complexes 3a−d were synthesized from the reaction of AlMe3 with the corresponding ligand
at room temperature by alkane elimination. All complexes were characterized by 1H and
13C NMR spectroscopy, and the molecular structures of complexes 3a, 3c, and 3d were
determined by X-ray crystallography. Luminescent properties of the ligands 2a−d and the
complexes 3a−d in solution were studied, and it was found that emission maxima of 3a−d
are in the range 519−582 nm, depending on the substituents on the aryl rings of their ligands.
Complexes 3a−d exhibit intense photoluminescence in the solid state, and the maximum
emission wavelengths at room temperature are in the range 532−552 nm.