Molecular design toward good hole transport materials based on anthra[2,3-c]thiophene: A theoretical investigation

The current work has investigated computationally the geometries, electronic properties, photostability, and charge transport parameters of anthra[2,3-c]thiophene (AcTH) and its 5,10-disubstituted derivatives using the density functional theory (DFT) at the B3LYP/6-31+G(d,p)//6-31G(d,p) level. Furthermore, the substituent effects on these properties are also presented. According to calculations, electron withdrawing substituents remarkably stabilize the HOMO and LUMO of AcTH, while electron donating ones slightly destabilize them. Calculations also reveal ethinylation and cyanation, which can reduce the hole and electron reorganization energies of AcTH, are good strategies to design materials with the high charge mobility. AcTH (10), DCCH-AcTH (3), and DCN-AcTH (8) are predicted to be good candidates for hole transport materials because they possess large hole mobilities, high air-stability, and low hole injection barriers. In particular, the good relationships between the electronic properties and the substituent σm constants are established for AcTHs, which present an efficient access to the molecular design of new materials.