Proton-Conducting Hydrogen-Bonded 3D Frameworks of Imidazo-Pyridine-Based Coordination Complexes Containing Naphthalene Disulfonates in Rhomboid Channels

Chem Asian J. 2019 Dec 2;14(23):4389-4394. doi: 10.1002/asia.201901338. Epub 2019 Nov 28.

Abstract

Coordination complexes of an olefinic molecule (PIP) containing pyridine and imidazopyridine moieties with ZnII /NiII metal salts were shown to exhibit appreciable proton conductivity. These complexes form 3D-hydrogen bonded frameworks containing rhomboidal channels that are occupied by uncoordinated 1,5-naphthalenedisulfonate (NDS). The extensive hydrogen bonding between the frameworks and NDS resulted in thermally stable and water-insoluble materials. Irrespective of the metal atom present, both complexes exhibited moderate to high proton conduction in the range of 10-5 to 0.5×10-3 S cm-1 depending on the temperature and humidity levels.

Keywords: coordination complexes; hydrogen-bonded frameworks; imidazo-pyridine; naphthalenedisulfonate; proton conductivity.