Syntheses, Structures, and Properties of Two Coordination Complexes of a Flexible Ligand with Channel Structure

Two complexes of 3,5‐bis(4‐carboxyphenylmethyloxy) benzoic acid (H 3 L) and transition metal ions, [Zn 2 (μ 3 ‐OH)(L)] · H 2 O ( 1 ) and (H 3 O)[Cu 2 (μ 4 ‐O)(L)] · H 2 O ( 2 ) were synthesized under hydrothermal conditions. Their structures were determined by single‐crystal X‐ray diffraction and further characterized by elemental analysis, IR and diffusion UV/Vis/NIR spectroscopy, and TGA. The complexes possess 3D open frameworks with different shapes (rhombus / square) and sizes of channels resulting from the trans/cis ‐configurations and coordination modes (μ 8 ‐η 1 :η 1 :η 1 :η 2 :η 1 :η 2 for 1 and μ 6 ‐η 1 :η 1 :η 1 :η 1 :η 1 :η 1 for 2 ) of the flexible ligand and the property of transition metal ions. In addition, photoluminescence spectra of 1 and 2 were also discussed. In 2 there exists antiferromagnetic interaction showing that μ 4 ‐O atom in {Cu 2 O} n chain does not favor the magnetic exchange between Cu 2+ ions.