Study Of The Electronic Structure Of The Vanadyl (Ii) Monochloroacetate Monomer Molecule

Abstract

In this work, density functional theory (DFT)–based quantum-chemical calculations were employed to investigate the molecular and electronic structure of vanadyl(II) acetate and vanadyl(II) monochloroacetate monohydrates. While the soluble tetrameric form of vanadyl(II) acetate hemihydrate has been experimentally synthesized, the monomeric monochloroacetate derivative has not yet been synthesized under laboratory conditions. To elucidate the reason for this synthetic inaccessibility, optimized geometries, bond parameters, and Mulliken charge distributions were determined, and the frontier molecular orbitals (HOMO and LUMO) were analyzed. The calculated HOMO–LUMO energy gap (ΔE), global reactivity descriptors, and potential energy distributions provided insight into charge-transfer processes and stability trends. Comparative analysis revealed that the monomeric monochloroacetate exhibits a larger HOMO–LUMO gap, suggesting enhanced electronic stability; however, cyclic bidentate coordination of the carboxylate group induces structural distortions within the vanadium coordination sphere. This electronic and geometric strain is identified as the most probable reason for the failure to synthesize vanadyl(II) monochloroacetate experimentally. The present findings highlight the importance of integrating quantum-chemical methods with experimental approaches for studying vanadyl carboxylates and related transition-metal complexes.