Since dipicolinic acid (DPA) is a dicarboxylic acid, it may be a system more favorable to put in evidence the possible association by hydrogen bonding of heteroaromatic molecules in aqueous solution [1]. It is a versatile ligand with the ability to act as a bidentate, tridentate, and/or bridging ligand. Therefore, it often appears as an organic linker in coordination polymers. It can interact with metal ions in both its fully deprotonated and partially deprotonated forms and is widely used for the preparation of the various metal−organic frameworks [2-4]. Thus, the main objective of the present work is to study the dimerization of unprotonated (N) and a partially deprotonated (Z) forms of DPA in the gas phase, with density functional theory (DFT) at the B3LYP/ 6-31G(d) basis set level. The basis set superposition error (BSSE) associated with the hydrogen bond energy in the dimerization of DPA was computed via the counterpoise method using the individual bases as fragments [5-7]. Also the molecular electrostatic potential (ESP) were calculated for DPA dimers. As seen from these calculated interaction energies, the stabilities of the dimer structures under investigation can explain the intermolecular hydrogen bonds formed in the dimers. We hope that our study provides an enhanced interpretation of DPA and its derivatives.

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