Construction of Four Coordination Polymers based on 2‐[4‐(Pyridine‐4‐yl)phenyl]‐1 H ‐imidazole‐4,5‐dicarboxylic Acid

The imidazole‐based dicarboxylate ligand 2‐(4‐(pyridin‐4‐yl)phenyl)‐1 H ‐imidazole‐4,5‐dicarboxylic acid (H 3 PyPhIDC), was synthesized and its coordination chemistry was studied. Solvothermal reactions of Ca II , Mn II , Co II , and Ni II ions with H 3 PyPhIDC produced four coordination polymers, [Ca(μ 3 ‐HPyPhIDC)(H 2 O) 2 ] n ( 1 ), {[ M 3 (μ 2 ‐H 2 PyPhIDC) 2 (μ 3 ‐HPyPhIDC) 26 (H 2 O) 2 ] · 6H 2 O} n [ M = Mn ( 2 ), Co ( 3 )], and {[Ni(μ 3 ‐HPyPhIDC)(H 2 O)] · H 2 O} n ( 4 ). Compounds 1 – 4 were analyzed by IR spectroscopy, elemental analyses, and single‐crystal and powder X‐ray diffraction. Compound 1 displays a one‐dimensional (1D) infinite chain. Compounds 2 and 3 are of similar structure, showing 2D network structures with a (4,4) topology based on trinuclear clusters. Compound 4 has another type of 2D network structure with a 3‐connected (4.8 2 ) topology. The results revealed that the structural diversity is attributed to the coordination numbers and geometries of metal ions as well as the coordination modes and conformations of H 3 PyPhIDC. Moreover, the thermogravimetric analyses of all the compounds as well as luminescence properties of the H 3 PyPhIDC ligand and compound 1 were also studied.