Structural Diversity and Dimensionality of Three Cu(II)-dpds-CO Coordination Polymers Controlled by the Coordination Sphere of Cu(II) Centers and the Coordination Modes of CO (dpds = 4,4'-Dipyridyldisulfide).

Three supramolecular architectures, [Cu(dpds)(CO)(HO)]·3HO (), [Cu(dpds)(CO)]·3HO (), and [Cu(dpds)(CO)]·9HO·CHOH () (dpds = 4,4'-dipyridyldisulfide and CO (croconate) = dianion of 4,5-dihydroxycyclopent-4-ene-1,2,3-trione), have been synthesized and structurally characterized. Compound contains two crystallographically independent Cu(II) ions, which are both distorted octahedral geometry with elongation along the croconate- and HO-bound axial positions and bonded with two N atoms of two dpds, two O atoms of one CO , and two HO molecules. Two crystallographically independent dpds ligands, both adopting the bis-monodentate bridging mode, connect two Cu(II) ions to form a one-dimensional zigzag chain-like coordination polymer. In and , there are two and three crystallographically independent Cu(II) ions, respectively, which are all distorted octahedral geometries with elongation along the croconate-bound axial positions six-coordinated and bonded with two N atoms of two dpds ligands in cis- or/and trans-forms and four O atoms of two CO ligands. The dpds ligands in and all adopt the bis-monodentate bridging mode, and the CO ligands act as bridging ligands with bridging bis-bidentate through three CO oxygen atoms in and bridging bis-bidentate through four adjacent CO oxygen atoms in , respectively, linking the Cu(II) ions to generate a two-dimensional layered and a three-dimensional metal-organic framework, respectively. The structural diversity and dimensionality observed in - may be attributed to the cis- or/and trans-coordination sphere of Cu(II) centers with two dpds ligands and the coordination modes of croconate ligands. Thermal stability and in situ temperature-dependent structural variations of - have been verified by thermogravimetric analysis and powder X-ray diffraction measurements. Compounds and both exhibit water vapor capture behaviors with hysteresis isotherms.