Electronic Characteristics of Halogenated Thioacetylacetone Derivatives: a Quantum-Chemical Study
Year: 2026
Type: article
Abstract: Thiocarbonyl compounds, in particular thioacetylacetone derivatives, are promising objects in coordination chemistry due to their propensity for tautomerism and the formation of chelate complexes. In this work, using modern quantum chemical methods, a systematic study was conducted on the effect of halogen substituents (F, Cl, Br, I) on the electronic structure and reactivity of the keto, enol, and thioenol forms of thioacetylacetone. The calculation of electronic characteristics was performed using the highly accurate ωB97M-D4/def2-TZVP functional. Dipole moments, isotropic polarizabilities, energies of frontier molecular orbitals, as well as parameters of absolute chemical hardness and softness were analyzed. The enol and thioenol forms possess significantly larger dipole moments than the keto form. The introduction of substituents at the γ-position sharply reduces the moment, up to the mutual cancellation of the vectors. The polarizability increases with the atomic number of the halogen, reaching its highest values in iodine-substituted structures. The energies of the frontier orbitals establish a clear hierarchy of reactivity: the enol form turns out to be the softest and most prone to orbitally controlled interactions, whereas the thioenol form is noticeably harder. For heavy halogens, the steric factor begins to dominate, distorting the molecular backbone. The established "structure–property" relationships allow for the targeted selection of thioacetylacetone derivatives with the desired polarizability and reactivity.
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W7203443334