Three New Complexes Based on the Flexible Zwitterionic Dicarboxylate Ligand: Synthesis, Structures, and Properties

Three new complexes have been prepared based on the transition metals and zwitterionic dicarboxylate ligand 1,1′‐(1,4‐phenylene‐bis(methylene))‐bis(pyridine‐3‐carboxylic acid) ( L ), whose formulas are {[Cd 4 ( L )(SO 4 )]· (Cl) 6 } n ( 1 ), [Zn( L) Cl 2 ] n ( 2 ), and [Co( L) Cl 2 ] n ( 3 ), respectively. Complexes 1 – 3 have been characterized by elemental analyses, IR spectroscopy, XRD, thermal analyses and single crystal X‐ray (powder) diffraction. 1 crystallizes in monoclinic space group C 2/ m , displaying a 2‐D layer structure with three unique Cd 2+ centers. 2 and 3 are isomorphic structures with the orthorhombic Cmca space group. They exhibit a 1‐D zigzag chain, which can be linked to generate a 2‐D layer via hydrogen bonding interactions (CH···O). Moreover, electrochemical behavior reveals that the redox reaction of 3 ‐CPE is a surface‐controlled reaction. And the luminescent properties of the title complexes have been investigated at room temperature.