Dipicolinic acid (DPA, DipicH2) is a multifunctional ligand can act as a bridging and a chelating ligand. It can interact with metal ions in fully deprotonated, partially deprotonated and unprotonated forms for preparation of the various metal-organic frameworks. Several modes of coordination are known for DPA: O-unidentate dipicH2; O,N-bidentate dipicH-; O,N,O-tridentate dipicH2, dipicH- and dipic2-; (O,N)O-bidentate bridging dipic2-; (O,N,O)O- and O,N µ-O-tridentate bridging dipic2-[1-3]. Since it is a dicarboxylic acid, it may be a system more favorable to put in evidence the possible association by hydrogen bonding [4]. We believe this versatility of DPA correlate with its ability for intramolecular hydrogen bonding and also its isomers [5]. Thus, the main objective of the present work is to study the intramolecular hydrogen bonding of DPA, with density functional theory (DFT) at the B3LYP/ 6-31G(d) basis set level. Nonspecific solvent effects have also been taken into account by using the conductor-polarizable continuum model (CPCM) of four different solvent. The barrier height for the hydrogen bonding decreases upon shifting from the water to the gas phase, while with increasing solvent dielectric constant, the formation of intramolecular hydrogen bond causes more stability. We hope that our study provides an enhanced interpretation of DPA and its metal complexes.

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