The role of Chlorine Interactions in the construction of Nickel(Ii) and Cobalt(Ii) Supramolecular Metal-Organic Frameworks Based on Mixed Tetrachloroterephthalate and 2,2'-Bipyridine Ligands

Abstract

Reactions of the rigid ligand 2,3,5,6-tetrachloro-1,4-benzenedicarboxylic acid (H₂BDC–Cl₄) with nickel(II) and cobalt(II) metal salts in the presence of 2,2'-bipyridine in DMF/MeOH afforded [M(BDC–Cl₄)(2,2'-bpy)(MeOH)₂] _n (M = Ni or Co). The Ni complex has a one-dimensional (1-D) linear structure that is further extended into a three-dimensional (3-D) supramolecular framework by inter-chain C–H···Cl hydrogen bonds, whereas the Co compound shows a 1-D zigzag structure, which is further assembled into a 3-D supramolecular architecture through intermolecular C–H···Cl and Cl···Cl interactions. These results reveal that weak chlorine interactions play an important role in governing these supramolecular structures. Thermal and fluorescence properties have also been investigated.