A new pseudopolymorph of diphenic acid and 4,4′-bipyridine co-crystal: Structural and theoretical study

• A new pseudopolymorph (B) of the diphenic acid and 4,4′-bipyridine is synthesized.
• Its solid-state structure is compared to the previously reported pseudopolymorph A.
• Interaction energies were investigated by AIM analysis and DFT calculations.

A new pseudopolymorph (B; tetragonal, I41/acd  ) of the cocrystal biphenyl-2,2′-dicarboxylic acid (diphenic acid) and 4,4′-bipyridine was synthesized. Its solid-state structure and supramolecular synthons responsible for extending the supramolecular network have been compared with those of the previously reported polymorph (A; triclinic, P1¯). DFT calculations at the B3LYP/6-311G++ (2d,2p) level have been performed. Energies of the intermolecular hydrogen bonds in the crystal structure were calculated and their electronic aspects were investigated by NBO and AIM analysis.

This research article reports a new pseudopolymorph (B; tetragonal, I41/acd  ) of the cocrystal diphenic acid and 4,4′-bipyridine, and combines experimental and theoretical approaches to compare its H-bonding interactions with those of the previously reported pseudopolymorph (A; triclinic, P1¯).Figure optionsDownload as PowerPoint slide