Exploring the nonlinear optical properties of fluorinated aniline derivatives: A computational and experimental study

This research focuses on the synthesis of derivatives such as 4-(4- tert -butylphenyl)-3-fluoroaniline ( BFPA ), 4-(1,1′-biphenyl-2-fluoroaniline) ( FPA ), 2-fluoro-4-(naphthalen-1-yl)aniline ( FNA ), 2-fluoro-4-(furan-2-yl)aniline ( FFA ), and 4′-amino-3′-fluoro-[1,1′-biphenyl]-4-ol ( AFPO ). Density Functional Theory (DFT) at the B3LYP/6–311 + G (2d,p) level and time-dependent DFT (TD-DFT) were applied to compare experimental spectroscopic data (NMR, FTIR, UV–Vis) with theoretical analysis (FMO, NPA, and NBO). The results showed full agreement between experimental data and DFT conclusions, highlighting how charge delocalization and hyperconjugation contribute to molecular stability. The global reaction characteristics calculated from FMO energy levels revealed that FPPM, with the highest ELUMO-HOMO of 4.91 eV, was the least reactive and most stable. NLO tests confirmed improved properties in the studied compounds, indicating their potential in photoelectric technology. • Synthesis and characterization of five fluorinated aniline derivatives, including BFPA, FPA, FNA, FFA, and AFPO. • Comprehensive DFT and TD-DFT analysis revealing the compounds' electronic structures and nonlinear optical (NLO) properties. • Experimental validation of molecular stability, polarizability, and dipole moment using FTIR, NMR , and UV–Visible spectroscopy. • FPA derivative shows the highest polarizability, indicating the most significant potential for optoelectronic applications. • Strong NLO responses observed in all compounds, with potential for use in organic light-emitting diodes (OLEDs) and organic solar cells (OSCs). • Theoretical insights into charge delocalization and intramolecular interactions contributing to the stability and functionality of the compounds. • Contribution to the design of advanced materials for the next generation of optoelectronic devices.