4-Imidazolecarboxylic acid (1H-imidazole-4-carboxylic acid, H2imc) is an imidazole derivative that contains an imidazole group and a carboxylate group. It has been widely utilized to generate different types of coordination polymers. The anion of 4-imidazolecarboxylic acid has been reported to stabilize binuclear hydroxo complexes of trivalent lanthanides in the pH range 7-10.