Pyrene appended terpyridine derivatives as electrochemiluminescence material for OLEDs: Characterization of photo-physical, thermal and electrochemical properties

Abstract

Three new terpyridine appended pyrene derivatives (Pyr-Tp, Pyr-Ph-Tp, and Pyr-Bp-Tp) have been synthesized by condensation and Suzuki-Miyaura reaction. The photo-physical, electro-chemical and thermal properties of these compounds have been investigated in detail. DFT studies have been carried out to understand the structure-property relationships at the molecular level. Synthesized fluorophores displayed high quantum yield (70-96%) of fluorescence due to triplet to singlet intramolecular energy transfer, delayed fluorescence and positive solvatochromism indicating the presence of intra-molecular charge transfer excited state. In addition, they have high thermal decomposition temperature (T_d: 390-450°C), melting temperature (T_m: 180-220°C) and further with suitable oxidation and reduction potentials makes them favourable molecules for OLED fabrications.