Computational Investigation of the Intermolecular Interactions between Decatungstate Acid and CX₂O (X=H, F, Cl, and Br)

Abstract

This study explores intermolecular interactions between the polyoxometalate (POM) compound, decatungstate acid, and CX2O (X=H, F, Cl, and Br). Initial optimizations were conducted using the PBE0 and M06‐2X /Lanl2DZ level of theory, renowned for adsorption studies. Computational results revealed a notable sequential increase in binding affinity for reactive compounds on POM surfaces optimized with PBE0, TPSSH, M06‐2X, CAM‐B3LYP, and ωB97XD/Lanl2Dz methods. Interestingly, the findings indicated a high binding affinity between reactive compounds and POM surfaces, affirming M06‐2X functional suitability for studying decatungstate acid interactions. Additionally, adsorption energy (Eads) values were negative, indicating stable adsorption processes. Careful examination of quantum theory of atoms in molecules (QTAIM), natural charge calculations, and hybridization calculations unveiled impressive intermolecular interactions, with non‐covalent interactions (NCIs) revealing deep blue iso‐surfaces in (CH2O@POM) and (CF2O@POM) complexes, indicating significant electrostatic force of interaction and presence of hydrogen bond interactions, enhancing POM surface‘s gas interaction capacity and smooth sensing. The analyzed complexes displayed slight increases in HOMO‐LUMO energy gap compared to POM, with the order of increase as follows: CH2O@POM (0.0819 eV)>CF2O@POM (0.0772 eV)>CBr2O@POM (0.0747 eV)>CCl2O@POM (0.0705 eV), suggesting POM′s suitability as an adsorbent. The study‘s major findings reveal the effective adsorption of CBr2O and CH2O facilitated by hydrogen bond interactions on the POM surface, making decatungstate acid a potential adsorbent for removing polluting gases from the atmosphere.