Synthesis and Investigation of Photophysical, Electrochemical and Theoretical properties of Phenazine-Amine based Cyan blue-Red Fluorescent Materials for Organic Electronics

To understand structure‒property relationship, we have designed and synthesized seven novel donor‒acceptor based phenazine‒amines 2−8 by Buchwald‒Hartwig coupling amination reaction in moderate yield. The synthesized molecules were fully characterized and studied for influence of modulating donor and phenazine core on optoelectrochemical properties. Absorption spectra of 2−8 display intramolecular charge transfer (ICT) transitions in the range of 431−501 nm. Dyes 2−8 exhibit positive solvatofluorochromism and emit in cyan blue‒red region with emission maxima 498–641 nm on excitation at their respective ICT maxima in toluene, chloroform, DCM and neat solid film. The photophysical studies of dyes in different THF/water mixture revealed aggregation induced emission (AIE) feature in dye 2, 3 and 5. The HOMO and LUMO energy level were found in the range of ‒5.39 to ‒5.68 eV and ‒3.59 to ‒3.71 eV with electrochemical band gap within the range 1.73−2.04 eV. Theoretical studies of molecules were also carried out by using TD‒DFT calculations. The comparable electrochemical energy level to ambipolar materials, solid state luminescence with AIE characteristic and good thermal stability of synthesized dyes signify their potential to be used as solid state emitter and ambipolar materials in optoelectronics.