Two new isomeric zinc(II) metal-organic frameworks based on 1,5-bis(2-methyl-1H-imidazol-1-yl) pentane and 5-methylisophthalate ligands

摘要

Many factors, such as temperature, solvent, the central metal atom and the type of coligands, may affect the nature of metal-organic frameworks (MOFs) and the framework formation in the self-assembly process, which results in the complexity of these compounds and the uncertainty of their structures. Two new isomeric Zn~II metal-organic frameworks (MOFs) based on mixed ligands, namely, poly[[μ-1,5-bis(2-methyl-1H-imidazol-1-yl)pentane-κ~2N~3:N~3'](μ-5-methyl-isophthalato-κ~2O~1:O~3)zinc(II)], [Zn(C_9H_6O_4)(C_13H_20N_4)]_n, (I), and poly[[μ-1,5-bis(2-methyl-1H-imidazol-1-yl)pentane-κ~2N~3:N~3'](μ_3-5-methylisophthalato-κ~3O~1:-O~1':O~3)(μ_3-5-methylisophthalato-κ~4O~1:O~1':O~3,O~3')dizinc(II)], [Zn_2(C_9H_6O_4)_2-(C_13H_20N_4)]_n, (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and thermogravimetric analysis. Complex (I) displays a two-dimensional layer net, while complex (II) exhibits a twofold interpenetrating three-dimensional framework. Both complexes show high stability and good fluorescence in the solid state at room temperature.