Quantum Mechanical Evaluation of Intramolecular Proton Transfer IPT in a New Hydrogen-Bonded [(DPAH)+(dipicH)−.H2O] Complex formed: NBO analysis and AIM Calculation, HOMO-LUMO

In this work, we showed theoretically the aromatic system of the hydrogen-bonded complex,[(DPAH)+(dipicH)−.H2O] formed by the reaction between 2,2 -dipyridylamineand (DPA) and 2,6-pyridine dicarboxylic acid (dipicH2) established the π–π stacking interactions, which have an important role in the stabilization of crystals with distance centroid-centroid (d: Cg-Cg). The proton transfer investigated theoretically and thermodynamic parameters such as ΔH‡, ΔG‡, ΔS‡ were calculated for this process [1-2]. Moreover, intramolecular hydrogen-bonding interaction has been recognized by calculating the electron density ρ(r) and Laplacian ∇2 ρ (r) at the bond critical point (BCP) using Atoms-In-Molecule (AIM) method. Also, the interaction between electron acceptor (σ*) of OH with the lone pair of the nitrogen atom as an electron donor was evaluated using Natural Bond Orbital (NBO) analysis [3].

Keywords:

Hydrogen-Bonded Complex , Stacking Interactions , Proton Transfer , AIM , NBO