Abstract
The organic compounds are known as an emerging class in the field of nonlinear optical (NLO) materials. In this paper, D-pi-A configured oxygen containing organic chromophores (FD2-FD6) were designed by incorporating various donors in the chemical structure of FCO-2FR1. This work is also inspired by the feasibility of FCO-2FR1 as an efficient solar cell. Theoretical approach involving DFT functional i.e., B3LYP/6-311G(d,p) was utilized to achieve useful information regarding their electronic, structural, chemical and photonic properties. The structural modifi-cations revealed significant electronic contribution in designing HOMOs and LUMOs for the de-rivatives with lowered energy gaps. The lowest HOMO-LUMO band gap obtained was 1.223 eV for FD2 compound in comparison to the reference molecule (FCO-2FR1) i.e., 2.053 eV. Moreover, the DFT findings revealed that the end-capped substituents play a key role in enhancing the NLO response of these push-pull chromophores. The UV-Vis spectra of tailored molecules revealed larger lambda maxvalues than the reference compound. Furthermore, strong intramolecular interactions showed the highest stabilization energy (28.40 kcal mol-1) for FD2 in the natural bond orbitals (NBOs) transitions, combined with the least binding energy (-0.432 eV). Successfully, the NLO results were favorable for the same chromophore (FD2) which showed the highest value for dipole moment (mu tot = 20.049 D) and first hyper-polarizability (beta tot = 11.22 x 10-27 esu). Simi-larly, the largest value for linear polarizability <alpha was obtained as 2.936 x 10-22 esu for FD3 compound. Overall, the designed compounds were calculated with greater NLO values as compared to FCO-2FR1. The current study may provoke the researchers towards designing of highly efficient NLO materials via using the suitable organic linking species.