Syntheses, crystal structures and photophysical properties of Ag(I) coordination complexes.

Three Ag(I) coordination complexes, [Ag(pyzca)]n (1) (Hpyzca=pyrazine-2-carboxylic acid), Ag[(HNA)(NA)(H2O)4] (2) (HNA=nicotinic acid) and [Ag1Ag2-(2,3-pydc)]n (3) (H2pydc=pyridine-2, 3-dicarboxylic acid) have been synthesized by the hydrothermal method. Their structures are determined by single-crystal X-ray diffractometer. Complex 1 possesses the 3D infinite structure. Complex 2 is a mononuclear coordination complex and exhibits one 3D infinite network by a large number of hydrogen bonds. In complex 3, two crystallographic independent Ag(I) ions exist, i.e., Ag1 is three-coordinate and Ag2 is two-coordinate, forming the 2D layer structure. At room temperature in the solid state, the IR, FP and UV-Vis spectra of all complexes were measured and investigated in detail. The emission and absorption spectra of the three complexes and their corresponding ligands are compared and analyzed.