Metal ion control of dimensionality and self-penetration in coordination polymers containing furandicarboxylate and dipyridylamide ligands

Article abstract of DOI:10.1016/j.ica.2016.07.026

Hydrothermal reaction of metal nitrates, 2,5-furandicarboxylic acid (H₂fdc) and the conformationally flexible dipyridylamide ligand 3-pyridylnicotinamide (3-pna) afforded three new coordination polymers which were structurally characterized by single-crystal X-ray diffraction. {[Cd₂(fdc)₂(3-pna)(H₂O)₄]·6H₂O}_n(1) exhibits a 1D ladder structural motif with tethering anti-conformation 3-pna ligands acting as the rungs. {[Ni(fdc)(3-pna)₂(H₂O)]·2.5H₂O}_n(2) displays a (4,4) rhomboid grid structure that resembles a rarer (3,6) triangular grid if supramolecular interactions provided by pendant syn-conformation 3-pna ligands are considered. [Co(fdc)(3-pna)(H₂O)]_n(3) manifests {Co₂(OCO)₂} anti-syn dimer-based 3-connected 4.8²layers pillared into a novel 3D 3,5-connected self-penetrated (4.6.8)(4.6⁵8³10) topology network by anti-conformation 3-pna ligands. The specific metal coordination environments, fdc binding mode, and 3-pna conformation act synergistically to enforce structure direction in this system. Thermal decomposition properties of these three new materials are also discussed.