Alpha-Terthiophene and its functionalized derivatives from roots of Echinops grijisii to produce potential organic semiconductor materials: A theoretical study

Abstract

DFT calculations were done to explore the optical and electronic properties of α-Terthiophene (α-TTP) and its functionalized derivates from Echinops grijisii, as potential organic semiconductors (OSCs). The properties estimated by the B3LYP-GD3/6–31 +G(d,p) technique include reorganization energy(λe and λh), ionization potential(IP), electron affinity(EA), and bandgap(Eg). The TD-DFT/CAM-B3LYP approach was also used to explore the λmax at the first excited states in vacuum. α-TTP is considered an n-type material, its functionalization resulted in a decrease in Eg and LUMO energy levels, indicating their potential use as n-type OSCs. All the molecules exhibit lower λe, which is in line with the IP and EA values. Compared to others, 5-Acetyl-α-TTP has stronger EA, lowest Eg, lower λe and LUMO confirming its better performance as n-type OSCs. The visualization of TDM maps, explains local excitation in all molecules. Moreover, the ESP map identifies variance in electron density in the skeletal backbone of studied molecules.