Crystal Structure and Luminescent Properties of Diverse Cadmium(II) Coordination Polymers Based on A Semirigid Multicarboxylate Ligand

Abstract

AbstractFour CdII metal coordination polymers, namely, [Cd(HL)(H2O)3]n (1), [Cd(HL)(4,4′‐bpy)]n·nH2O (2), [Cd3(L)2(2,2′‐bpy)3(H2O)3]n·2nH2O (3), and [Cd3(L)2(phen)2(H2O)]n·2.5nH2O (4) [H3L = 3‐(3‐carboxyphenoxy) phthalic acid, 4,4′‐bpy = 4,4′‐bipyridine, 2,2′‐bpy = 2,2′‐bipyridine, phen = 1,10‐phenanthroline], were synthesized and structurally characterized by X‐ray diffraction, elemental analysis, and IR spectroscopy. Single‐crystal X‐ray analyses reveal that complexes 1–3 have different one‐dimensional (1D) chain structures including zigzag chain, ladder chain, and helical chain, whereas complex 4 shows a 0D trinuclear motif. These low‐dimensional complexes are further extended to 3D supramolecular networks by intermolecular π–π interactions and hydrogen bonds. The ligand H3L exhibits five coordination modes: μ1‐η2‐chelating/μ1‐η2‐chelating, μ1‐η2‐chelating/μ1‐η2‐chelating/μ1‐η2‐chelating, μ1‐η2‐chelating/μ1‐η2‐chelating/μ1‐η1‐bridging, μ1‐η2‐chelating/μ2‐η2‐bridging/μ2‐η1:η1‐bridging, and μ2‐η2‐chelating:η1‐bridging/μ2‐η2‐chelating:η1‐bridging/μ1‐η1‐bridging. Moreover, the photoluminescent properties of complexes 1–4 were studied in the solid‐state at room temperature.