Alkyl substituents introduced into novel d(10)-metalimidazole-4,5-dicarboxylate frameworks: synthesis, structure diversities and photoluminescence properties

作者：Zhai, Quan-Guo^*; Zeng, Rong-Rong; Li, Shu-Ni; Jiang, Yu-Cheng; Hu, Man-Cheng

来源：CrystEngComm, 2013, 15(5): 965-976.

DOI：10.1039/c2ce26063h

• METAL-ORGANIC FRAMEWORK
• MOLECULAR BUILDING-BLOCKS
• ION-EXCHANGE PROPERTIES
• COORDINATION POLYMERS
• HYDROTHERMAL SYNTHESIS
• MAGNETIC-PROPERTIES
• CRYSTAL-STRUCTURES
• FLUORESCENT PROPERTIES
• ADSORPTION PROPERTIES
• DICARBOXYLATE LIGAND

Seven novel d(10)-metal-imidazole-4,5-dicarboxylate compounds namely [Zn(H2EIMDC)(2)(H2O)(2)]center dot 2.25H(2)O (1), [Ag-2(HPIMDC)(HPIM)(2)] (2), [Zn(HPIMDC)(H2O)](n) (3), {[Cd(H2PIMDC)(2)]}(n) (4), {(H3O)[Cd(MIMDC)]}(n) (5), {(H3O)[Cd(EIMDC)]}(n) (6) and {(H3O)[Cd-2(PIMDC)(HPIMDC)]}(n) (7), (H3MIMDC = 2-methyl-1H-imidazole-4,5-dicarboxylic acid, H3EIMDC = 2-ethyl-1H-imidazole-4,5-dicarboxylic acid, and H3PIMDC = 2-propyl1H- imidazole-4,5-dicarboxylic acid, HPIM = 2-propyl-1H-imidazole), have been synthesized by careful control of the synthetic conditions such as the solvent, pH value and the metal-to-ligand molar ratios. X-ray single-crystal structural analyses reveal that the change of alkyl groups on the 2-position of the ligand leads to the diversity of their structures, which range from discrete compounds (1 and 2), one-dimensional chain (3), two-dimensional layer (4) to three-dimensional frameworks (5, 6 and 7). Specially, under the same reaction conditions, the extending of the 2-position alkyl substitutents gradually reduces the symmetry of the ultimate 3D frameworks, which vary from tetragonal I4/mmm (5), tetragonal P4(2)/nmc (6) to orthorhombic Pbam (7) space groups. Alkyl-substituted imidazole-4,5-dicarboxylate ligands exhibit either singly, doubly, or triply deprotonated fashion, and coordinate to Zn(II), Cd(II) or Ag(I) ions in terminal mu(2)-, mu(3)- or mu(4)-modes. Compounds 1-7 have also been characterized by means of elemental analyses, X-ray powder diffractions, FT-IR, TGA and gas-adsorption. Furthermore, solid-state photoluminescence measurements show that all these d(10)-metal compounds produce strong blue emissions at room temperature.

• 出版日期2013
• 单位陕西师范大学