Charge transport modeling in bisphenazine derivative dimers as discotic liquid crystals: a TDDFT study

Abstract

A theoretical study was conducted on bisphenazine derivatives which behave as discotic liquid crystals (DLCs). Different cofacial dimeric conformations were studied in order to model the packing in a column, which is the main arrangement found in a DLC. The intermolecular charge transport process was assessed employing the charge transfer integral “J” in the context of Marcus theory. This parameter was obtained via the TD-Split method with the M06L functional and a basis set containing diffuse and polarization functions. The resulting systems display a charge displacement from one molecule to the other. Furthermore, a bonding interaction is observed in the frontier molecular orbitals; this suggests that the best geometries for effective electron transfer are those in which the molecules are rotated, and not eclipsed or widely displaced geometries. Additionally, computations of the monomer were performed to study the electronic structure and the electronic excitations. This methodology provided new insights into one-dimensional migration of charges in DLC compounds by employing TDDFT.