SEMI-EMPIRICAL INVESTIGATION OF ZINC(II) SALICYLATE. COMPARISON WITH X-RAY STRUCTURE.

Zinc salicylate dihydrate (Zn(HSal)₂·2H₂O) is an organic-inorganic hybrid compound known for its wide range of applications. In this article, a detailed semiempirical study of zinc salicylate is presented, focusing on its structural, electronic, and thermodynamic properties. The PM3 method, known for its computational efficiency and reasonable accuracy, was used to model the molecular structure and compare with the experimentally obtained properties of Zn(HSal)₂·2H₂O. Based on the obtained calculation results and available experimental data published in the literature, it was found that semi-empirical calculations involving the solvent effect (H₂O) agree well with data from X-ray diffraction analysis, while calculations for the gas phase do not agree with experimental data with the required accuracy. Quantum chemical descriptors such as HOMO-LUMO energies, energy gap (ΔE_gap), electronegativity (χ), global hardness (η), softness (σ), dipole moment (μ), electrophilic (ω) and nucleophilic (ε) indices were also calculated. The results show that the PM3 method effectively captures the essential features of zinc salicylate, including its geometry and electronic distribution. The obtained results also provide valuable insights into the semi-empirical modeling of organometallic compounds and highlight the usefulness of the PM3 method in predicting the behavior of complex molecular systems.