Exploration of optoelectronic, nonlinear and charge transport properties of hydroquinoline derivatives by DFT approach

Present investigation deals with an in depth study of three compounds including 4-(4-chlorophenyl)-8-methyl-2-oxo-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile (1), 4-(4-bromophenyl)-8-methyl-2-oxo-1,2,3,4,4a,5,6,7-octahydroquinoline-3-carbonitrile (2) and 8-methyl-2-oxo-4-(thiophen-2-yl)-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile (3) with respect to their structural, electronic, optical and charge transport properties. The ground and excited states geometries were optimized by density functional theory (DFT) and time dependent DFT, respectively. To rationalize the adopted methodology, the calculated geometrical parameters at ground state were compared with the experimental crystal structures. Several quantum chemical insights including the analysis of frontier molecular orbitals (FMOs), total/partial density of states (T/PDOS), molecular electrostatic potentials (MEP), local and global reactivity descriptors revealed that the studied compounds would be efficient multifunctional materials. The absorption wavelengths as well as their major transitions were thoroughly studied at TD-B3LYP/6-31G** level of theory. The smaller hole reorganization energies indicate that all these compounds might show better hole transport tendency. The anionic geometry relaxation of compound 2 is larger than the cationic form which leads to higher electron reorganization energy revealing the reduction of electron charge transport as compared to the hole.