Materials for organic electroluminescence: aluminium vs. boron

We report the synthesis of boron complexes 1–7 and their absorption and emission (photoluminescence and electroluminescence) characteristics in solution and in the solid state. We compare their electronic properties to those of the Alq3 analogues, and use molecular orbital (MO) calculations to rationalise the λmax shifts caused by systematically substituting methyl groups around the periphery of the 8-hydroxyquinoline ligand moiety.