Theoretical Investigation of 1-(4-Fluorophenyl)-3-(4-methylphenyl)triazene: DFT Analysis, NLO Properties, Chemical Reactivity, Hirshfeld Surface Analysis, and Molecular Docking

Abstract

1-(4-Fluorophenyl)-3-(4-methylphenyl)triazene (I) has been studied using an in-depth theoretical approach that combines density functional theory (DFT), Hirshfeld surface analysis (HSA), and molecular docking (MD). Complete geometry optimization was performed at the B3LYP/6-311++G(d,p) level, showing excellent agreement with experimental X-ray crystallography data (RMSD = 0.135 Å). The results confirm the reliability of the computational approach. The compound has an almost flat structure with conjugated π-electron systems, making it easier to delocalize the electrons. This is responsible for the optical properties. From the results, it is clear that the compound has good nonlinear optical (NLO) properties. The total dipole moment is 1.6673 D, and the first-order hyperpolarizability (βtot) is 9.0072 × 10-30 e.s.u. Frontier molecular orbital (FMO) analysis shows that the HOMO-LUMO energy difference is approximately 3.8 eV, showing that it is not very reactive. From the molecular electrostatic potential (MEP) surface, it is clear that the compound I has nucleophilic sites at the nitrogen and fluorine atoms. From the thermo-dynamic properties, it is clear that the heat capacity, entropy, and enthalpy increase with increasing temperature. From the HSA, it is clear that the compound I is held together by H···H (48.6%) and C···H/H···C (19.4%). Hydrogen bonds play an important role in the secondary interactions. MD of the compound I against the HER2 receptor showed a binding affinity of -9.3 kcal·mol-1, mainly through hydrophobic interactions with Met774, Leu785, Phe864, and Leu796. These results highlight the potential of the compound as a small molecule HER2 receptor antagonist. These results provide a better understanding of the electronic, structural, optical, and pharmacological properties of the compound I and establish the importance of the compound in optoelectronic and drug development fields.

Keywords

• Triazene
• DFT
• NLO properties
• HOMO–LUMO
• Hirshfeld surface analysis
• HER2 docking

References

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