A novel Ag(I) coordination polymers based on 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid: Syntheses, structures, ferroelectric, dielectric and optical properties

A novel metal–organic framework (MOF) {[Ag2(HPIDC)]}n (1), based on a T-shaped tripodal ligand 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylaic acid (H3PIDC), has been synthesized by hydrothermal method. The crystal structure of complex 1 is a three-connected net with the vertex symbol of (102·104·104), which represents ThSi2 (103-b) network topology. Complex 1 crystallizes in the noncentric space group (Cc), which belongs to the polar point group (Cs). The experimental results clearly show second-order nonlinear optical effects and ferroelectric feature. In addition, the photoluminescence of complex 1 was studied in solid state at room temperature.