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Five new metal–organic rotaxane frameworks (MORFs) have been hydrothermally synthesized by systematically combining cucurbit[6]uril-based pseudorotaxanes, rigid carboxylate ligands and d10 metal ions. Compound 1 presents a three-periodic pillared structure; 2 and 3 are two-periodic layers with hcb topologies; 4 presents a 3D structure with snw topology and 5 is a three-periodic network, featuring from interpenetrating to non-interpenetrating 3D MORFs. The cucurbit [6]uril-based MORFs obtained in this work illustrate the importance of non-covalent interactions around CB[6]s in the assembly of resultant super architectures. Furthermore, their TGA analysis, solid photoluminescence properties and sensitization to lanthanide ions are investigated. [ABSTRACT FROM AUTHOR]

Three polyoxovanadate-based metal–organic polyhedra (denoted as VMOP-1, -2, and -3), adopting isostructural discrete octahedral cage geometries, were successfully synthesized under solvothermal conditions. These structures are all built up from the same pentavanadate {V5O9Cl} cluster connected by linear bidentate ligands (H2L1 = H2BDC, H2L2 = H2BDC-NH2, H2L3 = H2BDC-Br), respectively. [ABSTRACT FROM AUTHOR]

Two unprecedented homochiral enantiomers based on two different kinds of rigid ligands, namely [Cd(NDC)L]2·H2O (1R and 1L), have been synthesized under hydrothermal conditions through spontaneous resolution. Their structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR, and thermogravimetric (TG) analysis. The resulting framework 1, constructed by four kinds of homo-handed helical chains represents the first 3D self-penetrating framework formed by decoration of single (10,3)-a net with helical chains. The single (10,3)-a net in 1 formed by three kinds of different homo-handed helical chains is different from the standard one, which should be ascribed to the usage of V-shaped ligand L. A unique self-penetration motif can be discovered in 1 where one helical chain alternately passes through 10-membered shortest circuits linked to each other and in contrary, the corresponding circuits are bound to the helical chain. Interestingly, 1 exhibits fluorescent emission in both the solid and solution phase. The uncoordinated nitrogen atom and amino group from the triazole core on the crystal surface make it suitable to detect picric acid in water. The luminescence intensity of 1 in water can be efficiently quenched by the addition of picric acid (PA). The sensitive detection of PA can be continuously performed for at least five cycles without diminishing the fluorescence intensity and destroying the framework structure of 1. The possible quenching mechanisms for PA are also investigated. [ABSTRACT FROM AUTHOR]

Six new Co(ii)-based mixed-ligand coordination polymers, namely, [Co2(H3bppc)2(2,2′-bpy)4]·H2O (1), [Co2(Hbppc)(2,2′-bpy)2(H2O)]·H2O (2), [Co(H2bppc)(H-bpp)]·2H2O (3), [Co3(μ3-OH)(bppc)(dps)(CH3CH2OH)]·4H2O (4), [Co2(bppc)(bib)(H2O)4]·(H2-bib)0.5·(H2O)3 (5), and [Co2(Hbppc)(bix)2]·2H2O (6), (H5bppc = biphenyl-2,4,6,3′,5′-pentacarboxylic acid, 2,2′-bpy = 2,2′-bipyridine, bpp = 1,3-bis(4-pyridyl)propane, dps = 4,4′-sulfanediyldipyridine, bib = 1,4-bis(imidazol-1-yl)benzene, bix = 1,4-bis(imidazol-1-ylmethyl)benzene), have been obtained under solvothermal conditions. 1 exhibits a 3D supramolecular framework based on a [Co2(H3bppc)2(2,2′-bpy)4] unit. 2 has a (3,4)-connected dmc net with a (4·82)(4·85) topology containing alternate binuclear metal clusters and single metal centres. 3 shows a 3D supramolecular architecture constructed from ladder-like arrays decorated with H-bpp. 4 exhibits a binodal (5,7)-connected 3D network based on trinuclear [Co3(μ3-OH)]5+ units with an unusual (3·46·52·6)(32·46·57·65·7) topology. 5 features a (4,6)-connected 3D fsc open framework with binuclear [Co2(H2O)(COO)]3+ units as nodes, and H2-bib and water molecules located in the voids of its framework by hydrogen bonds. 6 possesses a 3D net containing unusual 2D polyrotaxane sheets. Topological analysis reveals that 6 has a (3,4,4)-connected 3D network with a (4·6·74)(4·6·7)(6·72·102·11) topology. The structural difference of 1 and 2 is due to the different pH values of the reaction system. Though complexes 2–6 were synthesised under similar reaction conditions, the carboxylic groups of H5bppc were partially deprotonated in 2, 3 and 6 and fully deprotonated in 4 and 5. Complexes 2–6 display diverse structures depending on different N-donor ligands and the coordination modes of the multicarboxylate ligand. Variable-temperature magnetic susceptibility measurements reveal that complexes 1–6 show antiferromagnetic interactions. [ABSTRACT FROM AUTHOR]

A unique cationic metal–organic framework was synthesized by connecting the neutral rod-shaped secondary building unit with a cationic dicarboxylate ligand. This framework showed a rare snub square tessellation pattern by the periodic tiling of triangular and square nanotubes. The charge- and size-dependent ion-exchange of anion dyes was investigated. [ABSTRACT FROM AUTHOR]