Coordination polymers constructed from an asymmetric dicarboxylate and N-donors: preparation, characterization, and properties

Abstract

Two new coordination polymers with an asymmetric dicarboxylate and 4,4′-bipyridine ligand, {[Co (bpy)(H 2 O) 4 ]·(cpa)·0.5H 2 O} n (1) and {[Ag(cpa)(bpy)][Ag(bpy)]·4H 2 O} n (2) (H 2 cpa = 4-(2-carboxyethyl)benzoic acid, bpy = 4,4′-bipyridine), have been hydrothermally synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray diffraction. Compound 1 displays a chain with guest molecule (cpa) 2− ions existing in the structure. Compound 2 contains two independent units, [Ag(cpa)(bpy)] -(A) and [Ag(bpy)] + (B), which form a 1-D + 1-D structure. A shows a 1-D chain structure bearing hooks formed by the carboxylates and organized into a tubular structure by hydrogen-bonding interactions. B has linear chains formed from Ag + and bpy. The A and B chains co-crystallize with waters of crystallization to provide two linear [Ag(bpy)] + chains embedded in the tubular structure formed by A via π…π stacking contacts. In 1 and 2, hydrogenbonding and π…π stacking interactions connect the discrete 1-D chains into 3-D supramolecular structures. The fluorescent properties, TG analysis, and X-ray powder diffraction patterns for 1 and 2 were also measured.