Synthesis, properties, and X-ray crystal structures of two Ag(I) complexes with 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid

Abstract

Two 1-D and 3-D Ag(I) complexes involving 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid (H₃PIDC) have been characterized by infrared spectrum, elemental analysis, and single-crystal X-ray diffraction. [Ag₂(HPIDC)]_n (1), synthesized under hydrothermal conditions, gave a 3-D framework; [Ag₂(HPIDC)(MBI)]_n (2) (MBI = 2-methyl-1H-benzo[d]imidazole), with MBI as the second ligand, gave a 1-D zigzag chain and further formed a 3-D supramolecular structure through π···π interactions. The most interesting structural features of these complexes are the presence of C–H···Ag hydrogen bonding interactions and Ag···C weak interactions between the Ag centers and H₃PIDC. Luminescence indicates that 2 has significantly stronger fluorescent emissions than 1 in the solid state at room temperature.

Two new complexes formulated as [Ag₂(H₂PIDC)]_n (1) and [Ag₂(HPIDC)(MBI)]_n (2) {H₃PIDC = 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid, MBI = 2-methyl-1H-benzo[d]imidazole} have been synthesized and characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The most interesting structural features of these complexes are the presence of obvious C–H···Ag hydrogen bonding interactions and Ag···C weak interactions between the Ag centers and H₃PIDC ligands. In addition, their luminescent properties have been investigated in the solid state at room temperature.

Keywords:

• 2-(Pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid
• Ag(I) complexes
• Crystal structure
• Luminescence