Aryl azo imidazoles assisted assembly of anion/anion–water through salt formation

Abstract

Aryl azo dyes containing imidazole group can act as an acid or base. They are also potential hydrogen bond donor and acceptor. The imidazolium form of these dyes can form salts with various inorganic anions. The effect of the anion shape (linear, planner, spherical) on higher-dimensional supramolecular assembles of these salts has been analyzed and rationalized. Ligand assisted anion or anion–water assembly formation has been discussed. The presence of water in the crystal structure plays a vital role in the formation of higher dimensional networks. All supramolecular networks of salt 1–5 are guided by various noncovalent interactions, especially directional hydrogen bonds, halogen bonds and π-stacking interactions. The interaction of anions with the ligands in the solution phase was also investigated by absorption and fluorescent spectra.