Electron Density and Energy Decomposition Analysis in Hydrogen-Bonded Complexes of Azabenzenes with Water, Acetamide, and Thioacetamide

Abstract

Ab initio and density functional theoretical studies on hydrogen-bonded complexes of azabenzenes with water, acetamide, and thioacetamide have been carried out to explore the controversy involved in the relative order of their stability in a systematic way. The interaction energies of these complexes have been analyzed using the Morokuma energy decomposition method, and the nature of the various hydrogen bonds formed has been investigated through topological aspects using Bader's atom in a molecule (AIM) theory. Morokuma energy decomposition analysis reveals that the major contributions to the energetics are from the polarization (PL) and charge transfer (CT) energies. From the calculated topological results, excellent linear correlation is shown to exist between the hydrogen-bond length, electron density [rho(r)], and its Laplacian [nabla(2)rho(r)] at the bond critical points for all the complexes considered.

Intra and intermolecular hydrogen bonding in formohydroxamic acid

“…The hydrogen bond interactions are responsible for the variation in reactivity of the molecules. Their presence at the active site of enzymatic reactions has been suggested as the reason responsible for enhancing the rate of reaction 11–14. The intermolecular H‐bond interactions between the molecules of same type decide the crystal structural properties.…”

ZnO and TiO2 clusters as catalyst in the addition and abstraction reaction of acrylic acid with the OH radical

“…Further, the optimized coordinates of structures in abstraction and addition channels are given in Supporting Information Tables S1 and S2. The presence of hydrogen bonds between acrylic acid and metal clusters is verified with AIM (atoms in a molecule) analysis, and calculated values are given in Supporting Information Tables S3 and S4 correspond to TiO 2 and ZnO clusters, respectively. Further, an intrinsic reaction coordinate procedure was used to verify whether each transition state connects the designated reactants and products in both directions, using the Gonzalez‐Schlegel steepest descent path with mass‐weighted internal coordinates …”

Revealing halogen bonding interactions with anomeric systems: An ab initio quantum chemical studies

“…Further, the large exchange and repulsion terms also implies the feasibility of orbital overlapping between the two monomers. The exchange energy obtained from LMO-EDA analysis is similar to the charge transfer term in NEDA or Morokuma partitioning scheme [32]. The polarization terms are also attractive in nature in these interhalogen complexes and such effects are considered by the orbital interactions between monomers which further allows charge shift between the respective monomers [28b].…”