Syntheses, Structures, and Luminescent Properties of Two Alkaline Earth Metal Coordination Polymers from Hydroxymethyl Imidazole Dicarboxylate

Abstract

Two new alkaline earth metal coordination polymers, which are [Ba(H₂IDC)-(H₃HmIDC)(H₂O)₂]_n (I) and [Sr(H₂HmIDC)]_n (II) [H₃IDC = 1H-imidazole-4,5-dicarboxylic acid, H₄HmIDC = 2-(hydroxymethyl)-1H-imidazole-4,5-dicarboxylic acid), respectively, have been successfully synthesized under solvothermal conditions by employing H₄HmIDC as the starting material. Both compounds I and II were structurally characterized by diverse techniques, such as single crystal X-ray diffraction (CIF files CCDC nos. 1839705 (I) and 1839706 (II)), FT-IR spectra, powder X-ray diffraction, and thermogravimetric analyses. Compound I exhibits a two-dimentional (2D) coordination network with a (4, 4) topology based on dinuclear [Ba₂O₄] as second building units (SBUs). Whereas compound II features a 3D coordination framework based on infinite 1D inorganic chains as SBUs, which can be further simplified as a 5‑connected noy topology. In addition, the photoluminescent properties of both compounds I and II were also investigated.