Syntheses, structures, and photo-luminescence of three silver complexes with N-heterocyclic multicarboxylic acids and 4,4′-bipyridine

Abstract

Three coordination polymers, [Ag4(bpy)3(pztc)] n (1), {[Ag6(bpy)2(pztc)(CN)2] · 2.6H2O} n (2), and {[Ag2(H2pdtc)(bpy)2] · 3H2O} n (3) (H4pztc = pyrazine-2,3,5,6-tetracarboxylic acid, H4pdtc = pyridine-2,3,5,6-tetracarboxylic acid, bpy = 4,4′-bipyridine), have been synthesized and characterized by elemental analysis, IR spectra, thermogravimetric analysis, UV spectra, fluorescent spectra, and single-crystal X-ray diffraction. Complex 1 displays a 3-D network with infinite channels of about 6.4 × 3.1 Å2 along the a-axis. The structure of 1 can be simplified as a 3,4,4-connected framework. Complex 2 displays a 3-D network and can be simplified as a 6,6-connected pcu framework. Complex 3 shows a 1-D chain structure and the chains form a 2-D layer structure by hydrogen bonds. Complexes 1–3 emit intense fluorescence at around 500 nm on excitation at 340 nm, 320 nm, and 340 nm, respectively.