Seven Copper Coordination Polymers Based on 5‑Iodo-Isophthalic Acid: Halogen-Related Bonding and N‑Donor Auxiliary Ligands Modulating Effect

A series of copper coordination polymers of [Cu₃(OH)₂­(5-iipa)₂­(phen)₃­(H₂O)­·4.5­(H₂O)]_<i>n</i> (<b>1</b>) [Cu­(5-iipa)­(phen)­(H₂O)]_<i>n</i> (<b>2</b>), [Cu­(5-iipa)­(bpe)­·2­(H₂O)]_<i>n</i> (<b>3</b>), [Cu­(5-iipa)­(<i>p</i>-bix)]_<i>n</i> (<b>4</b>), [Cu­(5-iipa)­(bbi)]_<i>n</i> (<b>5</b>), [Cu₂(5-iipa)₂­(bbi)­·0.5­(H₂O)]_<i>n</i> (<b>6</b>), and [Cu­(5-iipa)­(bpp)­·H₂O]_<i>n</i> (<b>7</b>) (phen = 1,10-phenanthroline, bpe = 1,2-bis­(4-pyridyl)­ethane, <i>p</i>-bix = 1,4-bis­(imidazol-1-ylmethyl)-benzene, bbi = 1,1′-(1,4-butanediyl)­bis­(imidazole), bpp = 1,3-bi­(4-pyridyl)­propane) were hydro­(solvo)­thermally synthesized through the reaction of divalent copper salts, 5-iodo-isophthalic acid (5-H₂iipa), and N-donor ancillary ligands. Single-crystal X-ray diffraction analyses on these complexes revealed that noncovalent interactions were found to be predominant in constructing these supramolecular architectures. Compounds <b>1</b>–<b>5</b> all possess three-dimensional (3D) supramolecular structures based on O···I, I···I, I···π, and π···π interactions. Compound <b>6</b> exhibits a complicated three-dimensional (3D) framework with a new (6·7²)₂­(6³·7²·8)₂­(6³·7⁸·8²·9²) topology, while <b>7</b> features a 3D 3-fold interpenetrating network with a (4,4)-connected (3.8⁵)­(3²·8³·9) topology. A systematically structural description of these polymers indicates both halogen-related interactions and N-donor auxiliary ligands have a significant effect on the coordination network assembly. Their thermal analysis, X-ray diffraction, and UV–vis absorption spectra have also been investigated as well