Diverse Coordinative Functions of 4,4′‐Bipyridine Generating Abundant Weak Interactions and Novel Fluorescent Property in Cadmium(II)‐4‐sulfobenzoate Polymer

The cadmium(II) 4‐sulfobenzoate complex with 4,4′‐bipyridine, {[Cd₂(4,4′‐bipy)₄(4‐sb)₂(H₂O)₃] · 4H₂O}_n, has been synthesized and characterized by elemental analysis, IR, DTA‐TG, fluorescence analysis, powder X‐ray analysis, and single‐crystal X‐ray structural determination. Structural analysis showed that the complex contains two Cd atoms in an unsymmetrical unit. The Cd1 atom displays a seven‐coordinated geometry, which is a capped anti‐trigonal prismatic structure, whereas the Cd2 atom has an octahedral coordination. The 4,4′‐bipyridine ligands in the complex have three coordination behaviors, i.e., monodentate, dimeric linker, and polymeric bridge, which is the first example showing three coordinative functions for 4,4′‐bipyridine ligands in one complex. Moreover, three coordinative functions of 4,4′‐bipyridine ligands in this polymer lead to abundant weak interactions and novel fluorescent properties, which is benefit for design and preparation of functional materials in specific usage.