Optical and electrochemical properties of three-dimensional conjugated triphenylamine-azomethine molecules

The molecules bearing triphenylamine (TPA) structure were widely investigated mainly as active hole-transporting materials for construction of light-emitting diodes. Our previous research was concerned for poly(azomethines) bearing TPA in structure. Now we present research of its model compounds. A series of five conjugated azomethines have been synthesized in reaction of different aromatic diamines and 4-formyltriphenylamine. The structures of given azomethines were characterized by means of FTIR, 1H NMR, and 13C NMR spectroscopy and elemental analysis. Optical, electrochemical and thermal properties of all compounds were investigated by means of differential scanning calorimetry (DSC), UV–vis spectroscopy, photoluminescence spectroscopy and cycling voltammetry. Influence of chemical structure of the compounds on their properties has been analyzed.

► Synthesis of well defined oligomers being a model compounds of poly(azomethines).
► Description of optical, electrochemical and thermal properties of all compounds.
► Direct measurement of optical and electrochemical band gap.