Structures and fluorescence properties of two novel metal-organic frameworks based on the bis(2-benzimidazole) and aromatic carboxylate ligands

Two new metal-organic frameworks, [Cd2(H2C3PIm)(BDC)4(H2O)3]n (1) and [Zn3(H2C3PIm)3 (BTC)2(H2O)2]n (2) (H2C3PIm = 2,2′-(1,3-propanediyl)bis(1 H-benzimidazole), H2BDC = 1,4-benzenedicarboxylic acid, H3BTC = 1,3,5-benzene tricarboxylic acid), have been synthesized hydrothermally and their structures are characterized by single crystal X-ray analysis. Compound 1 presents a 1D columnar structure, and compound 2 exhibits a 2D sheet with novel extra-large rings of 4.82 topology. Both complexes exhibit strong photoluminescence at room temperature.

Graphical abstractTwo novel metal-organic frameworks based on the bis(2-benzimidazole), [Cd2(H2C3PIm)(BDC)4(H2O)3]n (1), [Zn3(H2C3PIm)3 (BTC)2(H2O)2]n (2), have been successfully prepared under hydrothermal conditions and characterized. Their fluorescence spectra have been studied, both complexes exhibit strong photoluminescence at room temperature.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights► Two new interesting Cd(II)-containing and Zn(II)-containing polymeric complexes , [Cd2(H2C3PIm)(BDC)4(H2O)3]n (1) and [Zn3(H2C3PIm)3(BTC)2(H2O)2]n (2) have been prepared. ► 1 presents a 1D columnar structure though three types of coordination modes with Cd ion, while compound 2 exhibits 2D grid structure with novel 32-membered and 64-membere rings of 4.82 topology. ► Both two complexes exhibit strong photoluminescence at room temperature.