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 Xray 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