The title complex was serendipitously obtained by reacting imidazole-4,5-dicarboxylic acid, tetraethylammonium hydroxide, 1,10-phenanthroline, and manganese(II) perchlorate hexahydrate in ethanol-water mixed solvent. It crystallizes in the monoclinic system, space group Cc with a = 24.8043(6), b = 8.7973(2), c = 24.2475(2)Å, β = 118.844(1)°, V = 4634.6(2)Å3 and Z = 4. A most noteworthy structural feature is that two counterions, namely Et4N+ and ClO4- cocrystallize in the crystal lattice.
