Analyzing the physical chemistry of the structural dynamics and stabilizing interactions of citrazinic acid‐ammonium formamide complex

Abstract

This paper studies the nature of the non‐covalent interactions in the complex formed by citrazinic acid and ammonium formamide (CA‐AF), employing the principles of density functional theory (DFT). The individual molecules of CA and AF, as well as their combined dimer CA‐AF, underwent optimization in a gas‐phase environment, utilizing the M062X/aug‐cc‐pVDZ approach. The study calculated the binding energy for the optimized dimer to evaluate its thermodynamic stability. To qualitatively dissect the nature of interactions within the CA‐AF complex, techniques such as the reduced density gradient (RDG) method and quantum theory of atoms in molecules (QTAIM) were applied. Charge distribution across the complex's atoms was scrutinized through Mulliken population analysis and natural population analysis. The study also explored the electronic characteristics of the complex, with a focus on charge delocalization, which was analyzed using natural bond orbital techniques. The investigation unveiled a notable hydrogen bond interaction between CA's hydrogen and AF's oxygen atoms, a finding corroborated by QTAIM analysis. This exploration enhances the understanding of non‐covalent bonding in complex molecular structures, offering valuable insights into molecular interaction dynamics.