Optoelectronic and charge transport properties of D-n-A type 1,3,5-triazine derivatives: A combined experimental and DFT study.

Abstract

The synthesis of five D-n-A type star-shaped octupolar molecules is presented in the current work. The exploration of the potential applicability of molecules under study in organic optoelectronics as electron or hole transporting materials is carried out by DFT methods. All the molecules have a 1,3,5-triazine core, which acts as an electron acceptor (A). Phenyl ring and pyridine ring act as electron donors (D) in AZ and PZ series of molecules respectively. The donor and acceptor core are connected by -NH bridge (n). The crystal structure of a molecule in the PZ series is elucidated. Thermogravimetric studies are carried out to confirm the thermal stability of molecules. The frontier molecular orbitals of molecules are characterized with the help of cyclic voltammetry. With the assistance of DFT methodologies, the whole research presented in this work focuses on the electronic excitations, reorganization energies, electron affinity, ionization potential and features of frontier molecular orbitals of molecules. The investigation of the variation of optoelectronic properties of molecules with changing patterns of nucleophilic substitution on 1,3,5-triazine core and presence of a hetero (nitrogen) atom in the donor part of the molecule is also accomplished.