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Two isomorphic acetylacetone-based complexes, trans-bis(acetylacetone)-1,4cyclohexanediimine (TBAC) and cis-bis(acetylacetone)-1,4-cyclohexanediimine (CBAC), were designed to promote complex formation on reaction with AgX (X = NO3-, ClO4-, BF4-, SbF6- and SO3CF3-) and were employed to generate nine silver coordination polymers (CPs), {[Ag(TBAC)]·2H2O·BF4}n (1), [Ag(TBAC)0.5(NO3)]n (2), [Ag2(TBAC)2(ClO4)2]n (3), [Ag(TBAC)(CF3SO3)(H2O)]n (4), {[Ag(TBAC)2]·SbF6}n (5), {[Ag(CBAC)]·BF4}n (6), {[Ag(CBAC)(H2O)]·ClO4}n (7), {[Ag(CBAC)(H2O)]·CF3SO3}n (8) and {[Ag(CBAC)(H2O)]·SbF6}n (9), that exhibit structural and topological diversity as determined by single-crystal X-ray diffraction analyses. The complexes were further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. Complex 1 exhibited a 3D (4,4)-connected pts topology with the Schläfli symbol of (42·84). The NO3- anions in 2 are μ2-bridging linkers, connecting the 1D [Ag(TBAC)0.5]n chains to 2D (3,4)-connected nets. In 3, TBAC is a tridentate ligand to bind Ag(I) ions to form a 1D ladder-like supramolecular structure. Complex 4 has 2D (3,3)-connected nets where both Ag(I) ions and TBAC ligands are 3-connected nodes. Complex 5 has a 1D fishbone chain structure where some of the TBAC moieties are bidentate. The cis isomer, CBAC, gives similar (3,3)-connected networks where the Ag(I) ions and CBAC ligands are 3-connected nodes in the resultant 6-9. Although the host networks in 6-9 are supramolecular isomers, structural comparisons revealed that use of cis and trans isomers of the ligand and different counterions significantly influence the structures. The luminescent properties of all complexes and ligands were investigated.

A novel hemimethyl-substituted cucurbit[7]uril (HMeQ[7]) derived from 3α-methyl-glycoluril has been prepared. HMeQ[7] is readily soluble in both water and dimethyl sulfoxide (DMSO) and displays not only host–guest interaction properties similar to those of the normal cucurbit[7]uril but also unusual properties in DMSO.

The interactions between a series of lanthanide cations (Ln

Interaction of a series of lanthanide cations (Ln3+) with a symmetrical octamethyl-substituted cucurbituril (OMeQ[6]) has been investigated. X-ray single-crystal diffraction analysis has revealed that the interaction results in the formation of adducts of OMeQ[6] with aqua complexes of lanthanide cations ([Ln(H2O)8]3+), Ln = Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb in OMeQ[6]–Ln(NO3)3–H2O systems. However, no solid crystals were obtained from systems containing La, Ce, Pr, Nd and Sm. X-ray diffraction analysis has revealed that although the solid adducts fall into two isomorphous groups, there are no significant differences in the interactions between OMeQ[6] and [Ln(H2O)8]3+ complexes and in the corresponding supramolecular assemblies. Thermodynamic parameters for the interaction between OMeQ[6] and [Ln(H2O)8]3+ complexes based on isothermal titration calorimetry experiments show two periods corresponding to the above two systems, with the lighter lanthanide cations preferring to remain in solution and the heavier lanthanide cations forming crystalline solids. Electron spectroscopy has shown that interaction of OMeQ[6] with lanthanide cations could provide a means of isolating heavier lanthanide cations from their lighter counterparts.

A convenient method to isolate inverted cucurbit[7]uril (iQ[7]) from a mixture of water-soluble Q[n]s was established by eluting the soluble mixture of Q[n]s on a Dowex (H(+) form) column so that iQ[7] could be selected as a ligand for coordination and supramolecular assembly with alkaline earth cations (AE(2+)) in aqueous HCl solutions in the presence of [ZnCl(4)](2-) and [CdCl(4)](2-) anions as structure-directing agents. Single-crystal X-ray diffraction analysis revealed that both iQ[7]-AE(2+) -[ZnCl(4)](2-) -HCl and iQ[7]-AE(2+) -[CdCl(4)](2-) -HCl interaction systems yielded supramolecular assemblies, in which the [ZnCl(4)](2-) and [CdCl(4)](2-) anions presented a honeycomb effect, and this resulted in the formation of linear iQ[7]/AE(2+) coordination polymers through outer-surface interactions of Q[n]s.

In the crystal structure of the title compound, 2C36H36N24O12·2C16H22N22+·4Br−·13H2O, the host cucurbituril is threaded by the guest hexane-1,6-diyldipyridinium cation to form a pseudorotaxane. Two Br− anions form hydrogen bonds with two solvent water mol­ecules, while the other solvent water mol­ecules inter­act with the carbonyl O atoms at the rims of the cucurbituril.

In the crystal structure of the title compound, C16H23N2+·Cl−·H2O, the mol­ecules and ions are linked through N—H⋯Cl, O—H⋯Cl, O—H⋯N and N—H⋯O hydrogen bonds. In addition, π–π stacking between pyridine rings leads to a tail-to-tail arrangement.

A number of linear coordination polymers have been assembled from lanthanide cations (Ln3+) and cucurbit[7]uril (Q[7]) in the presence of [CuCl4]2−or [CoCl4]2− anions acting as inorganic structure inducers in HCl solution. X-ray diffraction analysis has revealed that they form three groups of isomorphous structures. Generally, the complexes of Q[7] with light lanthanide cations (those with atomic number below that of neodymium (Nd3+)) are in one group. The other two groups, in which the lanthanide cation has atomic number greater than that of europium (Eu3+), seem to follow no obvious rule. For example, the complexes of Q[7] with Eu3+ and Gd3+cations are in the second group in the presence of [CuCl4]2− anions, while they are in the third group in the presence of [CoCl4]2− anions. However, whatever group a given complex belongs to, they all show a common honeycomb-patterned supramolecular assembly, in which [CuCl4]2−or [CoCl4]2− anions form a honeycomb structure. The Ln3+ cations then coordinate to neighboring Q[7] molecules to form 1D coordination polymers that are inserted into the channels of the honeycomb framework, such that each individual coordination polymer is surrounded by [CuCl4]2−or [CoCl4]2− anions.

Background Resveratrol, a natural plant polyphenol, has received increasing attention because its varied bioactivities, including the inhibition of tumorigenesis, lipid modification and calorie-restriction. We aimed to investigate the effect of resveratrol on oxidative/nitrative stress in endotoxemia-associated acute lung injury. Methods Mice were injected with lipopolysaccharide (LPS, 5 mg/kg, ip). Resveratrol at a dose of 0.3 mg/kg was administered alone or immediately before injection of LPS. Twenty four hours later, lung tissues were collected for histopathologic examination, and determination of malondialdehyde (MDA), H 2 O 2 , reduced/oxidized glutathione (GSH/GSSG) ratio, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, catalase (CAT) activity, inducible nitric oxide synthase (iNOS) expression, nitric oxide (NO) and peroxynitrite production. Results Resveratrol treatment improves histopathological changes in the lung during endotoxemia. Increased oxidative stress in endotoxemic lung was reversed by resveratrol treatment, as evidenced by the decreases of pro-oxidant biomarker (MDA and H 2 O 2 ), and the increases of anti-oxidant biomarkers (GSH/GSSG ratio, T-AOC, CAT and SOD activity). Treatment with resveratrol inhibited endotoxemia-induced iNOS expression and NO production. Moreover, peroxynitrite formation in endotoxemic lung was significantly attenuated after resveratrol treatment. Conclusions Resveratrol exerts protective effects against acute endotoxemia-associated lung injury. These beneficial effects may be due to both the anti-oxidant and anti-nitrative properties of resveratrol. These findings support the potential for resveratrol as a possible pharmacological agent to reduce acute lung injury resulting from oxidative/nitrative damage.

Using an established method, we isolated a large quantity of cucurbit[10]uril (Q[10]) and prepared Q[10]-based supramolecular assemblies via different approaches. For example, the structure-directing agent [CdCl4]2– was used or the Q[10] molecule itself acted as a self-structure-directing agent to form different Q[10]-based supramolecular assemblies through the outer surface interaction of Q[10]. Generally, the Q[10]-based supramolecular assemblies possess porous features that suggest that Q[n]-based compounds could be used to manufacture molecular sieves and sensors and applied in absorption and separation technologies.

There is intensive interest in the design of tubular channels because of their novel structures and various applications in a variety of research fields. Herein, we present a series of coordination-driven Q[7]-derived organic nanochannels using an anion-induced strategy under different acid concentrations. An advantage of this approach is that the tubular channels not only retain the original character of the parent macrocyclic receptors but also provide deep hydrophobic cavities possessing guest binding sites. Importantly, this study also emphasizes the efficiency of the macrocyclic receptors in providing a tubular hydrophobic cavity by directly stacking on top of one another with the anion-fixed and by acid control. The resulting combination of hydrogen bonding, C–H···Cl, and ion-dipole interactions helps to stabilize these supramolecular architectures. Such systems are both tunable and versatile and allow for interconvertibility in the construction of nanochannels based on these macrocyclic receptors.

The synthesis of the first family of fully substituted cucurbit[n]uril is discussed, and the structural features of precursor glycolurils are highlighted in their importance to achieving higher homologues. The members of the family, where n = 5-7, have been fully characterized, and increased binding affinities have been identified for dioxane in CyP(6)Q[6] and adamantyl NH(3)(+) in CyP(7)Q[7]. A higher homologue is indicated but not conclusively identified.

In the present study, we introduce the coordination of samarium–Q[5] systems in the absence and presence of the third species, and the corresponding supramolecular assemblies are dependent upon the addition of the third species. In the absence of the third species, a samarium cation (nitrate salt) coordinates to a Q[5] molecule and forms a molecular bowl; in the presence of an organic molecule (hydroquinone), a one-dimensional polymer of ···Sm–Q[5]–Sm–Q[5]–Sm··· is formed through direct coordination of Sm cation to the portal carbonyl oxygens. In the presence of nickel cations (chloride salt), an infinite 1D supramolecular chain is constructed of samarium/cucurbit[5]uril molecular bowl through ion–dipole interaction and hydrogen binding; in addition, the stacking of the supramolecular chains forms a novel hexagonal open framework. Remarkably, in the presence of copper cations (chloride salt), Q[5]-based hexagonal netting sheets are constructed of 6-Q[5]-ring structures.

Diastereopure (1R,2R)-N,N'-bis(acetylacetone)cyclohexanedi-imine L(1) and its corresponding (1R,2R)L(1)/(1S,2S)L(2) enantiomeric mixture react with AgNO(3) to yield the unusual coordination polymer [Ag(2)(L(1))(L(2))(NO(3))(2)](n) (1) and the unique trimetallic discrete species {[Ag(3)(L(1))(3)(micro(3)-O,O,O-NO(3))(H(2)O)(3)](2)(NO(3))}(NO(3))(3) x 8.5H(2)O (2) which incorporates a symmetrical micro(3)-bridging nitrato group that gives rise to a C(3)-symmetric triskelion motif; both species also feature gamma-carbon eta(1) aryl-like coordination of neutral bridging acetylacetone-imine units to the respective Ag(I) centres.

In the title compound, C12H11N3O3S·H2O, the pyridine ring makes a dihedral angle of 24.78 (14)° with the phenyl ring. Intramolecular N—H...O and intermolecular O—H...O hydrogen bonds are observed and stabilize the packing in the crystal structure.

In the crystal of the title compound, [Ni(NO3)2(C18H10N4)(H2O)]·H2O, the NiII ion is coordinated in a distorted octahedral geometry by two N atoms of the 1,10-phenanthroline moiety of the ligand, three O atoms from two nitrate anions and an O atom from one water molecule. O—H...O hydrogen bonds between the coordinated and the solvent water molecules and between these water molecules and the nitrate O atoms help to establish the crystal packing.

The organic cation of the title salt, C17H12N4O2+·2Cl−·H2O, is nearly planar, the dihedral angle between two pyridine rings being 2.53 (16)° and that between the pyridinum and furan rings being 4.17 (19)°. Molecules are linked via N—H...O, N—H...Cl and O—H...Cl hydrogen bonds, forming a three-dimensional framework and π–π stacking interactions help to stabilize the crystal structure [the imidazole–pyridine and imidazole–benzene centroid–centroid distances are 3.501 (3) and 3.674 (3) Å; respectively].

The asymmetric unit of the title compound, (C24H26N2)[ZnCl4], consists of two 2,2′-(hexane-1,6-di­yl)diisoquinolinium cations and two [ZnCl4]2− complex anions. The [ZnCl4]2− anions have a distorted tetra­hedral geometry. The dihedral angles between the isoquinoline rings of the two cations are nearly equal [16.1 (2) and 16.3 (2)°]. In the crystal structure, the ordered linear formation is aggregated by weak inter­molecular π–π stacking inter­actions between neighboring isoquinoline pyridine rings with a centroid–centroid distance of 3.779 (4) A.

The interaction of the diastereopure N,N'-bis(acetylacetone)cyclohexanediimine ligands, L(1)(1R,2R), L(2)(1S,2S), and their 1:1 mixture, with Zn(II) chloride has been investigated. Four new coordination polymers, [ZnL(1)Cl2 x H2O]n (1), [ZnL(2)Cl2 x H2O]n (2), [ZnL(2)Cl2]n (3), and [Zn6(L(2))6Cl12 x 2 H2O]n (4), each consisting of an infinite single helical chain displaying different pitches and/or handedness have been isolated. The complexed Schiff base ligands are present in their deprotonated enol forms, and the nitrogen atoms, which do not coordinate, are protonated because of proton transfer from the adjacent enol oxygen (coupled with concomitant N-H...O bond formation); each bound ligand is thus pseudo-zwitterionic. The respective zinc centers are bound to two chloro ligands and two oxygen donors from acacH-imine units belonging to different N,N'-bis(acetylacetone)cyclohexanediimine ligands such that the coordination at each zinc is distorted tetrahedral. Compounds 1 and 2, prepared from enantiopure L(1) and L(2), respectively, are enantiomers with similar structures, with the helical pitch in each being 17.0 A. Overall, the structure of 3 may be described as a one-dimensional helical chain with a pitch of 17.3 A, with each period corresponding to two L(2) ligands and two metal centers. The structure of [(Zn6L(2)6Cl12) x 2 H2O]n (4) contains six Zn(II) centers connected via six L(2) ligands to form a "bowed" helical repeat unit, with the pitch of the helix corresponding to 43.5 A. Supramolecular (intra- and intermolecular) aspects of all these unusual polymeric structures are discussed. Finally, the synthesis and characterization of an unprecedented six zinc-node discrete supramolecular assembly, [Zn6(L(1))3(L(2))3Cl12] (5), incorporating a 78-membered metallacycle, is also reported.

In the crystal structure of the title compound, C13H11N4O3+·Cl−, the dihedral angle between the two pyridine rings is 9.72 (9) Å. Ions are linked via N—H...Cl, O—H...Cl and O—H...O hydrogen bonds, forming a three-dimensional framework.

In the title compound, C(10)H(12)N(8)O(4)·H(2)O, prepared from the reaction of glycoluril with paraformaldehyde, the organic molecule has mm symmetry. The asymmetric unit comprises one quarter of the mol-ecule and a half-mol-ecule of water. The dimer is formed by bridging two glycoluril mol-ecules with methyl-ene groups at the 1 and 6 positions. In the crystal structure, mol-ecules are linked via N-H⋯O and O-H⋯O hydrogen bonds, forming a two-dimensional framework.

In the structure of the title compound, C(37)H(40)N(4)O(8), penta-erythrityltetra-mine is bonded to four o-vanillin mol-ecules, forming a four-armed Schiff base mol-ecule. These mol-ecules are connected by inter-molecular C-H⋯O hydrogen bonds. Intramolecular C-H⋯N and O-H⋯N hydrogen bonds are also present.

In the crystal structure of the title compound, C(6)H(8)N(2)O·CH(4)N(2)O·H(2)O, mol-ecules are linked via N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds, forming a three-dimensional framework.

Correction for ‘Supramolecular assemblies constructed from inverted cucurbit[7]uril and lanthanide cations: synthesis, structure and sorption properties’ by Qing Li et al., RSC Adv., 2016, 6, 77805–77810.

In the title compound, C(17)H(14)O(6), the benzopyran ring system is essentially planar and forms a dihedral angle of 6.84 (4)° with the other benzene ring. In the crystal structure, centrosymmetrically related mol-ecules are linked into dimers by O-H⋯O hydrogen bonds. The crystal packing is controlled by C-H⋯π and π-π stacking inter-actions involving the benzopyran and benzene rings, with centroid-centroid distances between 3.645 (2) and 3.986 (2) Å.

Three barrel-shaped artificial molecular capsules 1-3, based on normal cucurbit[5]uril (Q[5]) and decamethylcucurbit[5]uril (Me10Q[5]), were synthesized and structurally characterized by single-crystal X-ray diffraction. Encapsulation of a chlorine anion in the cavity of a Q[5] or Me10Q[5] to form closed a molecular capsule with the coordinated metal ions or coordinated metal ions and water molecules in the crystal structures of these compounds is common. The three complexes [Pr2(C30H30N20O10)Cl3(H2O)13]3+ 3 Cl- x 5 H2O (1), [Sr2(C40H50N20O10)(H2O)4Cl]3+ 3 Cl- x 2 (HCl) 19 H2O (2) and [K(C40H50N20O10)(H2O)Cl] x [Zn(H2O)2Cl2] x [ZnCl4]2- x 2 (H3O)+ x 8 H2O (3) all crystallize as isolated molecular capsules.

In the title compound, C24H26N44+·4Cl−·2H2O, the cation possesses a crystallographically imposed centre of symmetry. The crystal structure is stabilized by inter­molecular N—H⋯Cl, N—H⋯O and O—H⋯Cl hydrogen bonds, and by π–π stacking inter­actions.

The cation of the title compound, C26H28N42+.2 Cl−·4H2O, is centrosymmetric while the two Cl− anions are each located on a twofold rotation axis. Hydrogen-bonding and π–π stacking inter­actions help to stabilize the crystal structure.

Three new heterometallic coordination polymers (CPs) formulated as [NiAg3(acac)3(NO3)2(H2O)]n (2), [NiAg3(acac)3(ClO4)2(EtOH)2]n (3), and [NiAg2(acac)2(CF3SO3)2(H2O)2]n (4) have been obtained following a synthetic strategy of introducing AgX (X = NO3−, ClO4−, CF3SO3−) to react with a metalloligand [Ni(acac)2(EtOH)2]n (1, Hacac = acetylacetone). Their structures have been determined by single-crystal X-ray diffraction analyses and compounds 2–4 are further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. Complex 2 displays an unprecedented three-dimensional (3D) inorganic chiral framework with novel 5-nodal (3,3,4,4,4)-connected (4.82.103)2(42.6)(42.8.103)(43)(44.62)2 topology. Complex 3 possesses 2D inorganic layers holding 7-nodal (3,3,3,3,4,4,4,4)-connected (4.102)2(42.103.12)(42.6)(43)(44.62)2 networks. Complex 4 shows a 2D (4,5)-connected 4,5-L30 layered architecture with (33.4.62.74)(33.42.5) topology. The anions in compounds 2–4 are crucial factors for the formation of the different structures. In addition, the photoluminescent properties of compounds 2–4 are investigated in the solid state at room temperature.

The coordination and supramolecular assemblies of potassium/lanthanide cations to perhydroxycucurbit[5]uril in the presence of [PMo12O40]3− anions show significant differences, which could be used for the isolation of light lanthanides from their heavier counterparts.

Linear coordination polymers have been assembled from lanthanide cations (Ln3+) and cucurbituril (Q[6]) in the presence of [CdCl4]2− or [ZnCl4]2− anions as inorganic structure inducers in HCl solution. X-ray diffraction analysis has revealed honeycomb-patterned supramolecular assemblies, in which [CdCl4]2− or [ZnCl4]2− anions form the honeycomb and the hexagonal cells are occupied by Ln3+–Q[6] linear coordination polymers. For the Ln3+–Q[6]–[CdCl4]2− systems, the solid-state structures of the obtained compounds were all isomorphous, with the Ln3+ cations coordinated to Q[6] to form zigzag coordination polymers that fill the [CdCl4]2− honeycombs. For the Ln3+–Q[6]–[ZnCl4]2− systems, the obtained compounds were divided into two groups of four and five isomorphous complexes, respectively. Besides the zigzag coordination polymers, tubular coordination polymers occupying the [ZnCl4]2− honeycombs were also observed. The most remarkable phenomenon in the present work was the rapid precipitation of the Ln3+–Q[6]–[CdCl4]2− or –[ZnCl4]2− systems when the Ln3+ cations were La, Ce, Pr or Nd. This may offer a means of separating light lanthanides cations from their heavier counterparts.

A series of complexes based on the macrocyclic ligand cucurbit[7]uril (Q[7]) with formulas {La2(H2O)12Q[7]}·2(ZnCl4)·2Cl·31H2O (1), {Ln2(H2O)12Q[7]}·2(ZnCl4)·2Cl·xH2O [isomorphous with Ln = Ce (2), Pr (3) and Nd (4), x = 25 (2), 29 (3) and 25 (4)], and {Ln2(H2O)10Q[7]}·2(ZnCl4)·2Cl·xH2O [isomorphous with Ln = Sm (5), Gd (6), Tb (7), Er (8), Tm (9), Yb (10) and Lu (11), x = 24 (5), 27 (6), 27 (7), 33 (8), 27 (9), 18 (10) and 29 (11)], have been synthesized by the self-assembly of Q[7] with the corresponding lanthanide species in the presence of ZnCl2. The single-crystal X-ray diffraction analyses reveal that the eleven complexes are separated into three types of coordination nanotubes given different coordination environments of the lanthanide(III) ions. The eleven complexes display interesting structural progressions, which are mainly ascribed to the effect of lanthanide contraction. Their thermal and IR properties were also examined.

In the present work, we describe a kind of novel cucurbit[8]uril-based coordination supramolecular self-assembly taking place in the presence of tetrachloride transition-metal dianions ([MtransCl4]2−, Mtrans = Cd, Zn, Cu, Co) in HCl solution. As reported previously, the “honeycomb effect” of the tetrachloride transition-metal dianion ([MtransCl4]2− has been observed in the coordination of strontium cations to cucurbit[8]uril molecules (Q[8]s). It seems that the [MtransCl4]2− anions form a honeycomb structure with hexagonal cells filled with Sr2+–Q[8] linear coordination polymers in which the Sr2+ cations coordinate to Q[8] molecules and form zigzag coordination polymers.

To extend the strategy for the induced formation of cucurbit[n]uril–metal by a third species, we introduced alkali or alkaline earth metal ions (Malkali or alkaline earth metal) into cucurbit[8]uril (Q[8])–HCl systems in the presence of polychloride transition-metal anions. The polychloride transition-metal anions acted as structure inducers. A series of Q[8]–Malkali or alkaline earth metal complexes and their corresponding two-dimensional (2D) supramolecular assemblies were first synthesized and characterized by single-crystal X-ray diffraction analysis. The crystal structural analysis revealed that the Q[8]-based trigonal-planar branches in the related compounds are the key building blocks for the construction of the novel 2D Q[8]–Malkali or alkaline earth metal networks in which one or two alkali or alkaline earth metal ions link three Q[8] molecules through direct coordination. Moreover, the novel 2D Q[8]–Malkali or alkaline earth metal networks have a honeycomb shape with hexagonal “nanoholes”. The superimposition of the 2D networks could create novel nanochannels which numerous water molecules and counter anions could occupy.

We introduce an approach for the synthesis of networks based on the coordination of alkyl-substituted cucurbit[5]uril (SQ[5]), dimethylcucurbit[5]uril (DMeQ[5]), 1,3-dicyclohexanocucurbit[5]uril (1,3-DCyHQ[5]), 1,2,4-tricyclohexanocucurbit[5]uril (1,2,4-TriCyHQ[5]), 1,2,3-cyclohexanocucurbit[5]uril (1,2,3-TriCyHQ[5]), and pentacyclopentanocucurbit[5]uril (PCyPQ[5]) with K+ ions in the absence of a structure inducer. These novel SQ[5]-K+-based networks feature trigonal-planar branches constructed from three SQ[5]s and K+ ions in a triangular manner, in which the coordination of each K+ ion to the five portal carbonyl oxygen atoms of one SQ[5] as well as to a bridging portal carbonyl oxygen from an adjacent SQ[5] draws the edges of three portals into close proximity. Thus, a 3-K+-cation junction is formed at each portal of the S[5] and there are four 3-K+-cation junctions in which one or two coordinated water molecule(s) are shared by the three K+ cations in the trigonal-planar branch. Detailed inspection of the relationship of the planes at the 3-K+ junction has revealed that the dihedral angles between the junction plane and the center junction plane have a strong influence on the supramolecular assembly of SQ[5] with K+ ions into 2D-networks or 3D-frameworks. Moreover, these dihedral angles determine the structural conformation of the SQ[5]-K+-based networks and the superimposition of 2D-networks in the compounds.

The title compound [Cu4Cl6O(C7H6N2)4]·2C2H5OH, consists of the tetranuclear copper(II) complex and uncoordinated ethanol mol­ecules. The structure was reported previously by Tosik, Bukowska-Strzyzewska & Mrozinski [J. Coord. Chem. (1991), 24, 113–120], but only 0.68 ethanol mol­ecules were found in the asymmetric unit. The present redetermination indicates that two ethanol mol­ecules occur in the asymmetric unit. One ethanol molecule is ordered while the other one is disordered, with the hydroxyl group in two alternative sites. Both disordered hydroxyl groups hydrogen bond to the ordered ethanol mol­ecule with O⋯O separations of 2.845 (16) and 2.67 (2) A, and O—H⋯O angles of 156 and 147°, respectively.

A homochiral 1D-helical coordination polymer has been assembled from calcium ions (Ca2+) and cucurbit[5]uril (Q[5]) in the presence of p-hydroxybenzoic acid (Hyb) as an organic structure inducer. This result shows that a homochiral 1D-helical coordination polymer can be obtained from Q[5] with not only heavy lanthanides but also other metal ions, such as calcium dications in the present case, and that p-hydroxybenzoic acid (Hyb) can serve as an organic structure inducer in place of the previously used hydroquinone (Hyq). Control experiments by X-ray diffraction analysis have shown that Q[5] coordinates with the calcium cations to form a linear coordination polymer in the absence of Hyb, while a mixture of Q[5] and Hyb, without a metal salt under the same synthetic conditions, produces Q[5]-based linear supramolecular chains linked by hydrogen-bonding networks, which lie in a Hyb-based net.

Compared to a linear 1D coordination polymer of cucurbit[5] uril with Dy3+ ion, a pair of homochiral 1D-helical coordination polymers of cucurbit[5] uril with Dy3+ were obtained by spontaneous resolution upon crystallization in the presence of achiral hydroquinone, suggesting hydroquinone acts as an inducer of chiral helix.

Coordination polymers have been assembled from a series of eight different lanthanide ions (Ln3+) and cucurbit[5]uril (Q[5]) in the presence of hydroquinone (Hyq) as an organic structure inducer. X-ray diffraction analysis has revealed three distinct configurations of the coordination polymers formed with increasing atomic number of the lanthanide. The coordination of light lanthanide cations to Q[5] leads to the formation of linear one-dimensional coordination polymers; the coordination of intermediate lanthanide cations such as Eu(III) or Gd(III) leads to the formation of Q[5] pairs in which the two Q[5] molecules are connected by the Eu(III) or Gd(III) ions; and the coordination of heavy lanthanide cations to Q[5] leads to the formation of homochiral one-dimensional helical coordination polymers.

p-Hydroxybenzoic acid acts as a template in the presence of KI for the self-assembly of cucurbit[5]uril, which arranges into 6-membered ring structures. These form hexagonal netting sheets, superimposed upon one another to create continuous channels. This solid material is absorbent to volatile organics, ranging in size from methanol to 1,4-dioxane.

A strategy of using organic guest-induced formation of polymers or frameworks based on the coordination of metal ions and cucurbit[n]urils was developed. Using this strategy, a compound with a stoichiometry of {Rb2(μ-OH)(H2O)2(Hyq@Q[7])2}·Cl has been synthesized. X-ray crystallography, shows the crystal structure to be a novel three dimensional infinite framework, constructed by the Q[7] pairs through the hydroquinone-induced coordination of the rubidium unit to the portal oxygens of the Q[7]s.

Three novel coordination polymers {[K(H2O)](NO3⊂C30H28N20O20)[K(η2-NO3)]}Cl(H3O)22+·7H2O (1), {[Rb3(μ2-H2O)(μ3-H2O)(H2O)5SO4]+(H2O⊂C30H29N20O20)}Cl(H3O)+·2H2O (2), [Cs2(H2O⊂C30H26N20O20)]SO42−(H3O)44+ (3), were obtained by reactions of the corresponding alkali metal salts with an organic macrocyclic ligand perhydroxycucurbit[5]uril, (HO)10Q[5], and their structures were determined by single-crystal X-ray diffraction studies. The results revealed that, in complexes 1 and 3, the (HO)10Q[5] ligands are interlinked into two-dimensional networks through coordination of their carbonyl groups and hydroxy groups to the alkali metal ions (K+ and Cs+) in between, while in complex 2, the carbonyl groups and hydroxy groups of the (HO)10Q[5] ligands are coordinated by the Rb+ ions to form an acclivitous ‘ladder’ structure. Furthermore, solid-state packing of the complexes 1 and 3 shows the formation of open channels occupied by counterions and non-coordinating water molecules. The thermogravimetric analysis (TGA) of complex 1 was characterized.

A series of first generation dendritic guests from pentaerythritol derivatives have been designed and synthesized. Investigation of the complex structures of cucurbit[8]uril (Q[8]) and the guests based on the 1H NMR technique have revealed that the host Q[8] selectively included different branch(es) of the first generation dendritic guests and formed inclusion complexes with different structural conformations. The experimental results obtained from electronic absorption spectroscopy showed that the 1 : 1 ratio of Q[8]-based host–guest inclusion complexes have moderate stability with an average formation constants of 104 L mol−1. The single crystal structures of some of the guests (g5 and g6) and Q[8]–guest complexes (Q[8]-g4 and Q[8]-g6) further confirm but in some cases contradict the research results of the 1H NMR technique and electronic absorption spectroscopy in aqueous solution.

In the title compound, C8H12N4OS, an intramolecular N—H...O hydrogen bond links the imine N atom to the oxo O atom. In the crystal, molecules are linked by intermolecular N—H...O and N—H...S hydrogen bonds, forming a two-dimensional framework.

In the title compound, C(21)H(26)N(4) (2+)·Cl(-)·NO(3) (-)·H(2)O, the organic cations, anions and water mol-ecules are linked through N-H⋯Cl, N-H⋯O, N-H⋯N and O-H⋯Cl hydrogen bonds, forming a three-dimensional framework, assisted by C-H⋯π inter-actions.