A series of coordination polymers, namely, [Zn(μ3-L)(H2O)2] (1), [Zn(μ2-L)(2,2’-bpy)(H2O)] (2), [Zn(μ3-L)(μ2-4,4’-bpy)0.5] (3), [Cd(μ3-L)(2,2’-bpy)] (4), and [Cd(μ2-L)(phen)(H2O)] (5) (H2L = 3-carboxy-1-(3’-carboxy-benzyl)-2-oxidopyridinium, 2,2’-bpy = 2,2’-bipyridine, 4,4’-bpy = 4,4’-bipyridine, phen = 1,10-phenanthroline), have...