Effect of solvent and temperature on the photoluminescent properties of Ag(I) complexes base on two different flexibility imidazole functionalized benzoic acid linkers

Two novel Ag(I) complexes zero-dimensional (0D) [Ag(ibz)(Hibz)]₂ (Ag1) (Hibz = 4-(1H-imidazolyl)benzoic acid) and two-dimensional (2D) [Ag(imbz)(Himbz)]_n (Ag2) (Himbz = 4-(1H-imidazolyl-1-methyl)benzoic acid) have been synthesized through the hydrothermal method. By changing the ligands from rigid Hibz to flexible Himbz, the distance between two aromatic rings in the ligand is controlled to get different dimensional complexes. Both complexes have been characterized by single-crystal X-ray diffraction, infrared (IR), elemental analysis and thermal gravimetric analyses (TGA). Ag1 is coordinated with two nitrogen atoms, forming a two-coordination linear configuration. While Ag2 possesses interesting 2D frameworks, exhibiting two-fold interpenetrating sql topology structure. The luminescent properties of Ag1 and Ag2 are investigated both in the solid state and in different solvents (DMSO, CH₃CN and CH₃OH) at 298 K and 77 K. Ag1 displays stable blue luminescent in the solid state and in solvents at 298 K and 77 K. Whereas, Ag2 shows tunable luminescence by changing the temperature from 298 K to 77 K, indicating thermochromic luminescence for Ag2. The emission efficiency of Ag1 and Ag2 is found with quantum yields ranging from 0.073 to 0.208, which is much higher than that of free ligand.