Computational Exploration of 2-Fluoro-4-Nitrotoluene as a Multifunctional Electron-Accepting Chromophore for Photovoltaic, Nonlinear Optical, and pharmacokinetic Assesment: A DFT, TD-DFT, ADME, and SCAPS-1D Investigation

<title>Abstract</title> <p>2-Fluoro-4-nitrotoluene (2F4NTN) was investigated through a comprehen sive computational framework combining Density Functional Theory (DFT), Time-Dependent Density Functional Theory (TD-DFT), SCAPS-1D simula tion, and ADME analysis to evaluate its multifunctional potential in pho tovoltaic, nonlinear optical (NLO), and pharmacokinetic applications. Ge ometry optimization at the B3LYP/6-31+G and B3LYP/6-311++G levels confirmed the structural stability of the molecule. Frontier molecular or bital analysis revealed a HOMO–LUMO energy gap of 4.475 eV, indicat ing good electron-accepting ability and molecular stability. TD-DFT cal culations predicted efficient intramolecular charge transfer accompanied by fluorescence quenching, suggesting favorable charge separation. SCAPS- 1D simulation of the FTO/TiO2/2F4NTN/PEDOT:PSS/Au device yielded a power conversion efficiency (PCE) of 0.439%, with Voc = 0.822 V and Jsc = 6.13 mA cm−2 . Enhanced hyperpolarizability demonstrated promis ing NLO behavior, while ADME results indicated favorable pharmacokinetic characteristics. The study highlights 2F4NTN as a multifunctional candidate for energy, photonic, and biomedical applications.</p>