Structure- Propery Relationship of Molecule 474D : A Combined Study of Geometry Optimization, IR Spectra and Global Reactivity Parameters

The present work reports a comprehensive theoretical investigation of the structure–property relationship of molecule 474D using density functional theory (DFT). Geometry optimization was performed to obtain the most stable molecular conformation, and detailed structural parameters such as bond lengths, bond angles, and dihedral angles were analyzed to elucidate the three-dimensional molecular architecture and conformational stability. The absence of imaginary frequencies in the optimized structure confirms that the molecule corresponds to a true minimum on the potential energy surface.Vibrational frequency calculations were carried out to simulate the infrared (IR) spectrum of molecule 474D, enabling reliable assignment of characteristic vibrational modes associated with functional groups present in the molecular framework. The calculated IR frequencies show good agreement with standard vibrational ranges, validating the optimized geometry and the computational approach employed.To establish the structure–property correlation, global chemical reactivity descriptors—including highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, energy gap, electronegativity, chemical hardness, chemical softness, and electrophilicity index—were evaluated. The HOMO–LUMO energy gap provides insight into the electronic stability and chemical reactivity of the molecule, while the global reactivity parameters offer a quantitative measure of its potential behavior in chemical and biological environments.Overall, the combined analysis of geometry optimization, IR spectral characteristics, and global reactivity parameters provides a coherent understanding of the structure–property relationship of molecule 474D. The results highlight the stability, electronic distribution, and vibrational features of the molecule, suggesting its possible relevance in future physicochemical or pharmaceutical applications.