The influence of pH on coordination of phthalate to copper(II)

Two phthalate structures and a copper coordination polymer, (phth)(2)(H2O)(2) (1), (phth)(2)(H2O)(3) (2), and Cu(phth)(2)(H2O)(2) (3) [phth = phthalate], have been synthesized hydrothermally. The complexes were studied by single crystal X-ray analysis, elemental analysis, IR spectra and TG-DTG. Single crystal X-ray analysis reveals that 1 belongs to the orthorhombic system, space group Pca2(1), 2 is the monoclinic system, space group C2/c and 3 has four-coordinate Cu(II). The copper complex forms a one-dimensional zigzag chain via pi-pi stacking interaction of phthalates. Adjacent zigzag chains may be paired by supramolecular recognition and attraction through both pi-pi stacking and hydrogen bonding interactions into molecular zippers, further interlinked into a three-dimensional supramolecular network by these noncovalent interactions.