ZnII/CdII-coordination polymers from 1D chain, 2D layer to 3D framework with imidazole-based dicarboxylate ligand

Three ZnII/CdII-coordination polymers based on 2-propyl-4,5-imidazoledicarboxylate (H3pimdc), namely, [Zn(Hpimdc)H2O]n (1), [Cd(H2pimdc)2]n (2) and [Cd2(Hpimdc)2(bbi)0.5(H2O)2]n [bbi = 1,10-(1,4-butanediyl)bis(imidazole)] (3), have hydrothermally been synthesized, which exhibit a systematic dimensional variation by changing the metal ions or introducing the auxiliary ligand. Complex 1 is a 1D zig-zag polymeric chain, which is finally extended into a 3D supramolecular network through R44 (12) O–H⋯O H-bonding rings. Complex 2 shows a 2D layer comprised alternately arranged left- and right-handed helical chains. Complex 3 features a rare (3,3)-connected 83 network with opposite chiral layers in a slipped ABAB fashion. The photoluminescent properties and thermal stabilities of three complexes are also discussed.

Graphical abstractThree new coordination polymers exhibit a systematic dimensional variation from 1D zig-zag chain, 2D layer comprised alternately arranged 21-helical chains, to 3D achiral 83 network with opposite chirality parallel plane.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Complex 1 is a 1D zig-zag polymeric chain. ► Complex 2 shows a 2D layer composed alternately arranged 21-helical chains. ► Complex 3 features a 3D achiral network with opposite chiral parallel plane. ► The photoluminescent and thermal properties of three complexes were discussed.