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A simple protocol for the rapid synthesis of chalcogen-containing compounds by an I2O5-promoted oxidative Csp2–H selenation and seleno/thiocyanation of activated arenes is reported here.

A time-economical and robust synthesis of selenofunctionalized heterocycles by an I2O5-promoted selenylative heterocyclization of olefins with easily accessible diselenides is reported herein.

In this paper, the host-guest interaction of cucurbit[7]uril (Q[7]) and chromone (CMO) has been developed as a fluorescent probe for the highly selective detection of Zn2+ and Cd2+ in water based on a chelation-enhanced fluorescence (CHEF) mechanism. There was a good linear relationship between the fluorescence intensity of the CMO@Q[7] probe and the concentration of Zn2+ or Cd2+ in the range of 0–3.0 × 10–5 mol/L and the detection limit for Zn2+ and Cd2+ was found to be 2.03 × 10–6 mol/L and 1.89 × 10–6 mol/L, respectively. The X-ray crystal structure indicated that different coordination fashions were triggered by Zn2+ and Cd2+ in the CMO@Q[7] complexes, respectively. However, both metal ions coordinated with the carbonyl oxygen of CMO, which was encapsulated in the cavity of Q[7], thus leading to the enhancement of recognition fluorescence emission of CMO.

The semiconductors, such as TiO2, CdS, ZnO, BiVO4, graphene, produce good applications in photocatalytic water splitting for hydrogen production, and great progress have been made in the synthesis and modification of the materials. As a two-dimensional layered structure material, graphitic carbon nitride (g-C3N4), with the unique properties of high thermostability and chemical inertness, excellent semiconductive ability, affords good potential in photocatalytic hydrogen evolution. However, the related low efficiency of g-C3N4 with fast recombination rate of photogenerated charge carriers, limited visible-light absorption, and low surface area of prepared bulk g-C3N4, has called out the challenge issues to synthesize and modify novel g-C3N4-block photocatalyst. In this review, we have summarized several strategies to improve the photocatalytic performance of pristine g-C3N4 such as pH, morphology control, doping with metal or non-metal elements, metal deposition, constructing a heterojunction or homojunction, dye-sensitization, and so forth. The performances for photocatalytic hydrogen evolution and possible development of g-C3N4 materials are shared with the researchers interested in the relevant fields hereinto.

The semiconductors, such as TiO

By using the method of building blocks, the dodecamethycucurbit[6]uril Me12Q[6] was synthesized and its structure was characterized by multiple techniques. The binding interactions between Me12Q[6]...

A physical impregnation method is presented in this study, providing a facile approach to encapsulating functional guest molecules (GMs) into robust crystalline supramolecular organic frameworks incorporating cucurbit[10]uril (Q[10]-SOF). As Q[10]-SOF has high evaporated pyridine affinity under normal atmospheric pressure, pyridine molecules in this method were successfully encapsulated into the nanospace formed by GMs and Q[10]-SOF while retaining their crystal framework, morphology, and high stability. GMs@Q[10]-SOF solid materials were found to respond to pyridine, being suitable to be used as solid sensors. Notably, Q[10]-SOF loading with pyrene exhibited a unique response to pyridine along with dramatic fluorescence quenching; loading with dansyl chloride exhibited a unique response to pyridine along with significant fluorescence enhancement, having a quick response within 60 s. Our findings represent a critical advancement in the design of pyridine detection and adsorption for commercial gas identification and sensing.

Curcurbit[n]uril (Q[n])-based supramolecular frameworks (QSFs) constructed from the outer surface interaction of Q[n]s (OSIQ) have the characteristic of simplicity, diversity and modulability. Their simplicity is reflected in their simple composition and preparation methods used for QSFs. The diversity of supramolecular organic frameworks (SOFs) is reflected in the synthesis methods and structural characteristics of the as-obtained QSFs, as well as the variety of structural directing agents and basic building blocks used to prepare QSFs. The modulability is reflected by the controllable channel size in the QSFs, which can be adjusted using different sizes of Q[n]s. In this work, the first reported cucurbituril Q[6] was selected as the basic building block and three Q[6]-based supramolecular frameworks were obtained from aqueous HCl solutions in the presence of [CdCl4]2− respectively. The OSIQs are the main driving forces for the formation of these frameworks. This study shows the diversity of the QSFs.

An intermolecular aminoselenation of alkenes with sulfonimides and diselenides is achieved via a visible-light-induced three component reaction. A broad variety of aminoselenation products is accessible in good yields with excellent functional group compatibility. Additional features of this new protocol include being additive- and photocatalyst-free and the use of natural sunlight as well as suitability for the modification of styrene-functionalized biomolecules. Mechanistic investigations suggest that the transformation occurs through a sequence of radical additions and nucleophilic substitutions.

Cucurbit[n]uril(Q[n])-based supramolecular frameworks assembled through outer surface interactions are characterized by their simple composition, convenient preparation, high yields and controllable structures. The most prominent characteristic of these frameworks is their diversity, with various synthesis methods, structural characteristics, structure directing agents and basic building blocks of Q[n]s. In this work, a symmetric tetramethyl-substituted Q[6] (TMeQ[6]) is selected as the basic building block, with three different TMeQ[6]-based supramolecular frameworks obtained from 1-, 3- and 5 mol/L aqueous H2SO4 solutions, respectively. The outer surface interactions between TMeQ[6] and the adjacent SO42− anions or TMeQ[6] units are the main driving forces for the formation of these frameworks, which exhibit adsorption properties for fluorophore dyes and organic isomers. These adsorption characteristics may lead to the application of these frameworks in the synthesis of solid fluorescent sensors for volatile organic compounds and the adsorptive separation of alkane isomers.

The anion-induced outer surface interaction of Q[

A time-economical and robust synthesis of various selenofunctionalized heterocycles was accomplished

Atypical luminescent compounds that do not contain conventional chromophores emit light due to clustering and have important basic research value and a broad range of potential applications. To date, most atypical luminescent compounds are small molecules or polymers containing groups such as cyano, carbonyl and hydroxyl. In this work, driven by some sporadic and accidental luminescence phenomena observed for cucurbit[n]urils (Q[n]s), the luminescent properties and mechanism of Q[n]s in the solid- and solution-state were systematically studied and the clustering emission of Q[n]s confirmed. Our experiments have revealed that the self-induced outer-surface interactions of Q[n]s (OSIQ) are the most important driving force resulting in the clustering emission of Q[n]s. Substances that can weaken the effect of self-induced OSIQ, such as the presence of various aromatic compounds and anions, may weaken or quench the clustering emission of Q[n]s. This not only reveals the new characteristics and mechanism of the clustering emission of Q[n]s, but also provides new insights on how to utilize the clustering emission of Q[n]s and construct new types of macrocyclic luminescence systems.

The development of cucurbit[n]urils–polyoxometalate (Q[n]–POM) hybrids with the same microshape and nanoscale features is highly desirable, yet remains a great challenge. Herein, we design and synthesize a class of Q[n]–POM hybrids and tetramethyl cucurbit[6]uril–phosphomolybdic acid (TMeQ[6]–PMA) nanocubes (NCs) via a facile one-step self-assembly method, as heterogeneous acid catalysts for greatly boosting the catalysts in term of activity and stability for the esterification of gallic acid and n-propanol to propyl gallate (PG). The Fourier transform infrared (FTIR) spectroscopy reveals that the self-assembled mechanism of TMeQ[6]–PMA NCs based on the outer-surface interaction of Q[n]s. The temperature programmed desorption experiments with ammonia and FTIR analysis of the pre-adsorbed pyridine results confirm that the coexistence of medium and strong acid sites and a larger number of Lewis acid sites other than Bronsted acidic sites on the catalyst surface. These new features make the as-prepared TMeQ[6]–PMA NCs exhibit a high PG conversion (95.6%) and excellent stability, which represents a better catalytic performance than other reported catalysts.

The coordination of alkaline earth metal cations (AE2+ = Mg2+, Ca2+, Sr2+, Ba2+) with inverted hexamethylcucurbit[3,3]uril {iMe6Q[3,3]} has been investigated in the presence of polychlorido cadmium anions as structure directing agent. Single-crystal X-ray diffraction analysis has revealed that the interactions of iMe6Q[3,3] with AE2+ cations result in the formation of linear iMe6Q[3,3]-based coordination polymers from iMe6Q[3,3]-AECl2-CdCl2-HCl systems. Generally, Cd2+ cations can form [CdCl4]2− anions that serve as structure directing agent in the formation of iMe6Q[3,3]/AE2+-based coordination polymers. Moreover, iMe6Q[3,3]-AECl2-CdCl2-HCl systems exhibit high affinity for the heavier AE2+, such as Sr2+, and Ba2+.

Herein, we report the facile preparation of two solid luminescent materials made from cucurbit[10]uril-based porous supramolecular assemblies, from simple precipitation of cucurbit[10]uril (Q[10]) in HCl solution (A) or HNO3 solution (B). Loading Q[10]-based porous supramolecular assemblies A or B with various fluorophore guests (FGs), including dyes and fused ring compounds, to yield solid luminescent materials (FG@As and FG@Bs) that exhibited fluorescence enhancement or colour changing fluorescence emission. Moreover, these solid luminescent materials could respond to certain volatile organic compounds, demonstrating promise as solid sensors.

Mechanical ventilation (MV) and lipopolysaccharide (LPS) infection are common causes of acute lung injury. The aim of the present study was to identify the key genes and potential mechanisms involved in mechanical ventilation (MV) and lipopolysaccharide (LPS)-induced acute lung injury (ALI). Gene expression data of adult C57BL/6 mice with ALI induced by inhaling LPS, MV and LPS + MV were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) associated with MV, LPS and LPS + MV were screened, followed by functional enrichment analysis, protein-protein interaction network construction, and prediction of transcription factors and small molecule drugs. Finally, the expression of key genes was verified in vivo using reverse transcription-quantitative PCR. A total of 63, 538 and 1,635 DEGs were associated with MV, LPS and LPS + MV, respectively. MV-associated genes were significantly enriched in the ‘purine ribonucleotide metabolic process’. LPS and LPS + MV-associated genes were significantly enriched in ‘cellular response to cytokine stimulus’ and ‘cell chemotaxis’. All three conditions were enriched in ‘TNF signaling pathway’ and ‘IL-17 signaling pathway’. Expression levels of C-X-C motif chemokine ligand (CXCL)2, CXCL3 and CXCL10 were upregulated in the LPS and LPS + MV groups. Adenosine A2b receptor, zinc finger and BTB domain-containing 16 and hydroxycarboxylic acid receptor 2 were identified as DEGs in the MV group. Compared with the control group, Early growth response 1 and activating TF 3 was upregulated in all three groups. Similarities and differences were observed among the MV- and LPS-induced ALI, and MV may enhance the effects of LPS on gene expression. MV may affect urine ribonucleotide metabolic-related processes, whereas LPS may cause cell chemotaxis and cytokine stimulus responses in ALI progression. The inflammatory response was shared by MV and LPS. The results of the present study may provide insight into a theoretical basis for the study and treatment of ALI.

We report herein a cucurbit[10]uril-based porous supramolecular assembly (A) that is readily obtained in the presence of [ZnCl4]2− as a structure-directing agent in HCl solution. Loading the Q[10]-based porous supramolecular assembly A with various fluorophore guests, including various dyes and fused-ring compounds, yielded solid luminescent materials showing fluorescence enhancement or quenching or emission color change. Moreover, these solid luminescent materials could respond to certain volatile organic compounds. In particular, the assembly obtained by loading A with 1,8-diaminonaphthalene exhibited a distinct response to formaldehyde and could be used as a solid sensor.

Q[8]-based honeycomb-like frameworks can be obtained in [AuCl4]--free aqueous HNO3 solution and aqueous HCl and HNO3 solutions that contain [AuCl4]-. The outer surface interaction of Q[8] with planar inorganic anions [AuCl4]- and NO3- is the main driving force. These frameworks exhibit a high selectivity for imprisoning [AuCl4]- that could establish a process for gold recovery.

Two perhydroxylated cucurbit[6]uril-based supramolecular assemblies have been obtained via crystallization of perhydroxylated cucurbit[6]uril {(HO)12Q[6]} from aqueous HCl solutions of different concentrations. Single-crystal X-ray diffraction (unit cell) analysis revealed that (HO)12Q[6] molecules interacted with water molecules through hydrogen bonding, thereby forming solid supramolecular assemblies with different kinds of channels. These selected channels were formed from the stacking of (HO)12Q[6] molecules in a portal-to-portal manner and between the outer surfaces of (HO)12Q[6] molecules. Unlike normal or alkyl-substituted Q[n]-based supramolecular assemblies, which generally exhibit highly selective absorption of methanol, the (HO)12Q[6]-based supramolecular assemblies exhibit highly selective absorption of polychloromethanes.

We report the preparation and single crystal X-ray diffraction analysis of three supramolecular self-assemblies based on perhydroxycucurbit[5]uril {(HO)10Q[5]}, Keggin-type heteropolyacids (HPAs), and potassium or barium cations. Crystallographic data revealed that all 3D self-assemblies are constructed by a stack of 2D layered structures composed of (HO)10Q[5]/K+ or (HO)10Q[5]/Ba2+ complexes cations and HPAs anions. Although there are differences in 2D layered structures, all the driving force comes from the outer surface interactions of (HO)10Q[5] including: (1) typical hydrogen bonding by hydroxyl groups and atypical hydrogen bonding by methylene on the outer surface of (HO)10Q[5]; (2) dipole interaction between the positively charged methylene or carbonyl carbon atoms of (HO)10Q[5] and the negatively charged oxygen atoms of the HPAs; (3) The electrostatic interaction between the (HO)10Q[5]/metal cations and the HPAs anions plays a main role in self-assembling.

The esterification reaction used to prepare butyl paraben (BP) and propyl gallate (PG) catalyzed using a cucurbit[6]uril-supported Keggin-type silicotungstic acid (Q[6]-STA) catalyst has been investigated. The Q[6]-STA catalyst has been characterized using FTIR spectroscopy, XRD, SEM, EDS, thermal analysis, and surface area studies. Q[6]-STA was easy to prepare in high yield and exhibited some advantageous properties, such as high catalytic activity and its convenient recovery. Moreover, a reusability study showed that the Q[6]-STA catalyst was stable and active.

Mono-, di, and tri-hydroxylated hexamethylcucurbit[3,3]urils {(OH)Me6Q[3,3], (OH)2Me6Q[3,3], and (OH)3Me6Q[3,3]} have been prepared through a photochemical method whereby limited hydroxyl group(s) can be directly introduced on the parent symmetrical hexamethylcucurbit[3,3]uril (Me6Q[3,3]), These three hydroxylated Me6Q[3,3]s have been characterized by means of NMR, MS, and X-ray crystallographic techniques. Further chemical allylation of these hydroxylated Me6Q[3,3]s has also been performed.

Cucurbit[10]uril (Q[10] or CB[10]), with the largest rigid cavity (ca. 1.0 nm) yet characterized in the cucurbiturils family, and indeed among all artificial macrocyclic receptors to date, has been successfully exploited to construct a novel Q[10]–[Cd4Cl16]8–-based pillared diamond porous supramolecular framework. Single-crystal X-ray diffraction analysis revealed that the three-dimensional open-nanotube-type porous framework is constructed from free Q[10] molecules and [Cd4Cl16]8– cluster anions through the outer surface interactions of Q[10]. Notably, the Q[10]-based porous framework host can accommodate guest dyes, such as rhodamine B (G1), pyrenemethanamine hydrochloride (G2), and bathocuproine hydrochloride (G3), to form solid materials with efficient red-green-blue (RGB) fluorescence. This work not only exemplifies a facile approach for the construction of macrocycle-based porous frameworks but also offers a simple, lower cost, yet still highly efficient means of preparing multi-emitting, including ...

A new inverted cucurbituril, namely inverted hexamethylcucurbit[3,3]uril (iMe6Q[3,3]), has been isolated and characterized. It incorporates a single inverted un-substituted glycoluril unit oriented towards the interior of the cavity, shows good solubility in water and organic solvents (DMSO), and exhibits different selecties for guests to those of iQ[6] and other known Q[6]s.

We investigated the interactions in an inverted cucurbit[6]uril ( i Q[6]) with a series of 1, ω -alkyldimins and their supramolecular assemblies in the presence of the tetrachlorozincate anion ([ZnCl 4 ] 2− ) structure directing agent. i Q[6] forms an outer surface interaction with [ZnCl 4 ] 2− to form different i Q[6]/[ZnCl 4 ] 2− -based supramolecular assemblies with different length 1,ω-alkyldimins. Interestingly, most 1,ω-alkyldimins were not visible in crystals structures in the presence of concentrated HCl. The porous i Q[6]/[ZnCl 4 ] 2− -based supramolecular assemblies could be used as materials for adsorbing volatile compounds.

BACKGROUND Fibrotic change is one of the important reasons for the poor prognosis of patients with acute respiratory distress syndrome (ARDS). The present study investigated the effects of hydrogen-rich saline, a selective hydroxyl radical scavenger, on lipopolysaccharide (LPS)-induced pulmonary fibrosis. MATERIAL AND METHODS Male ICR mice were divided randomly into 5 groups: Control, LPS-treated plus vehicle treatment, and LPS-treated plus hydrogen-rich saline (2.5, 5, or 10 ml/kg) treatment. Twenty-eight days later, fibrosis was assessed by determination of collagen deposition, hydroxyproline, and type I collagen levels. Development of epithelial-to-mesenchymal transition (EMT) was identified by examining protein expressions of E-cadherin and α-smooth muscle actin (α-SMA). Transforming growth factor (TGF)-β1 content, total antioxidant capacity (T-AOC), malondialdehyde (MDA) content, catalase (CAT), and superoxide dismutase (SOD) activity were determined. RESULTS Mice exhibited increases in collagen deposition, hydroxyproline, type I collagen contents, and TGF-β1 production in lung tissues after LPS treatment. LPS-induced lung fibrosis was associated with increased expression of α-SMA, as well as decreased expression of E-cadherin. In addition, LPS treatment increased MDA levels but decreased T-AOC, CAT, and SOD activities in lung tissues, indicating that LPS induced pulmonary oxidative stress. Hydrogen-rich saline treatment at doses of 2.5, 5, or 10 ml/kg significantly attenuated LPS-induced pulmonary fibrosis. LPS-induced loss of E-cadherin in lung tissues was largely reversed, whereas the acquisition of α-SMA was dramatically decreased by hydrogen-rich saline treatment. In addition, hydrogen-rich saline treatment significantly attenuated LPS-induced oxidative stress. CONCLUSIONS Hydrogen-rich saline may protect against LPS-induced EMT and pulmonary fibrosis through suppressing oxidative stress.

The binding interactions of CyP6Q[6] with a series of alkyl diammonium (+H3N(CH2)nNH3+, n = 2, 4, 6, 8, 10, 12) and aryl diammonium (p-phenylenediammonium and p-xylenediammonium) ions both in aqueous solution and in the solid state have been studied by 1H NMR spectroscopy, X-ray crystallography, and isothermal titration calorimetry (ITC) techniques. 1H NMR data indicate that all guests exhibit endo binding with CyP6Q[6] except for the ethanediammonium ion, which bound exo to CyP6Q[6]. p-Xylenediammonium ions show mixed behavior (exo and endo binding with CyP6Q[6]). X-ray crystallography clearly displays the extended and contorted conformations of the guests when bound within CyP6Q[6]. The ITC study points out that the CyP6Q[6] complex formations with all guests are mainly driven by enthalpy, which arises from the ion–dipole interactions and the hydrophobic effects.

The interactions of alkali metal (A+ = Na+, K+, Rb+, Cs+) and alkaline earth metal cations (AE2+ = Mg2+, Ca2+, Sr2+, Ba2+) with mono-hydroxylated octamethylcucurbit[6]uril {(OH)OMeQ[6]} have been investigated in the presence of polychloride cadmium anions as structure-directing agents. Single-crystal X-ray diffraction analysis has revealed that the interactions of (OH)OMeQ[6] with A+ or AE2+ cations results in the formation of (OH)OMeQ[6]-based coordination complexes from (OH)OMeQ[6]–ACl or AECl2–CdCl2–HCl systems, in which Cd2+ cations form [Cd2Cl8]4− or [CdCl4]2− anions that serve as structure-directing agents in the formation of (OH)OMeQ[6]/A+ or AE2+-based supramolecular assemblies.

The interaction of a series of lanthanide cations (Ln3+) with a di-hydroxylated symmetrical octamethyl-substituted cucurbituril {(OH)2OMeQ[6]} has been investigated. Single-crystal X-ray diffraction analysis has revealed that the interaction results in the formation of adducts of (OH)2OMeQ[6] with aqua complexes of lanthanide cations ([Ln(H2O)8]3+), Ln = Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in (OH)2OMeQ[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 (OH)2OMeQ[6] and [Ln(H2O)8]3+ complexes and in the corresponding supramolecular assemblies. Thermodynamic parameters for the interaction between (OH)2OMeQ[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. Energy dispersive spectroscopy (EDS) has shown that the interaction of OMeQ[6] with lanthanide cations could provide a means of isolating heavier lanthanide cations from their lighter counterparts.

Interactions of alkali cations (A+ = Na+, K+, Rb+, Cs+) with a symmetrical octamethyl-substituted cucurbituril (OMeQ[6]) have been investigated in the presence of different structure-directing agents. Single-crystal X-ray diffraction analysis has revealed that the interaction results in the formation of coordination complexes of OMeQ[6] with K+ and Cs+ cations in OMeQ[6]–ACl–HCl systems, whereas no complexes were obtained from systems containing Na+ and Rb+ in the presence of polychloride cadmium anions such as [Cd2Cl8]4−, [CdCl4]2−, or [Cd2Cl7]3− as structure-directing agents; in the presence of p-hydroxybenzoic acid (Hyb) as a structure-directing agent, the interaction results in the formation of coordination complexes of OMeQ[6] with Na+ and Cs+ cations in OMeQ[6]–ACl–H2O systems. More importantly, in the presence of these different structure-directing agents, OMeQ[6] or OMeQ[6]/A+ complexes can form different supramolecular assemblies based on the outer surface interaction of Q[n].

In this study, fully substituted cyclopentano cucurbit[5]uril (CyP 5 Q[5]) were coordinated with an alkaline earth cations (AE 2+ ) in the presence of tetrachlorozincate anions ([ZnCl 4 ] 2− ). Single-crystal X-ray diffraction analysis revealed that the CyP 5 Q[5]–Mg 2+ –[ZnCl 4 ] 2− –HCl interaction system yielded an Mg 2+ /Cl − @CyP 5 Q[5]-type molecular bowl, with a chloride anion in the cavity of the CyP 5 Q[5] moiety. The CyP 5 Q[5]–Ca 2+ and Sr 2+ –[ZnCl 4 ] 2− –HCl interaction systems yielded isolated AE 2+ /CyP 5 Q[5]/AE 2+ -type molecular capsules, again with a chloride anion in the CyP 5 Q[5] cavity. A honeycomb effect was evident in all three systems, in which the of the [ZnCl 4 ] 2− anions surround the CyP 5 Q[5] molecules through outer surface interactions between Q[n] and electrostatic interactions with AE 2+ cations, resulting in the formation of porous supramolecular assemblies. Direct coordination between Ba 2+ and CyP 5 Q[5] yielded zigzag coordination polymers. The CyP 5 Q[5]/AE 2+ -based supramolecular assemblies (AE = Mg, Ca, Sr, Ba) presented different porous conformations and displayed differential absorption of volatile compounds.

Coordination of an inverted cucurbit[7]uril (iQ[7]) with a series of alkali cations (A+), revealed that iQ[7] can interact with potassium to form iQ[7]-K+-based porous coordination polymer in the presence of [ZnCl4]2 − anions as a structure directing agent. Unexpectedly, isothermal titration calorimetry revealed no obvious interaction of iQ[7] with any A+ cation. Moreover, the iQ[7]-K+-based porous coordination polymer showed selective sorption of polar volatile organics, which may have potential applications for molecular sieves, sensors, and absorption and separation processes.

We have investigated the interactions of the lanthanum cation (La3 +) with cucurbit [6]uril (Q [6]) and its alkyl-substituted derivatives (SQ [6]s), including symmetrical tetramethylcucurbit [6]uril (TMeQ [6]), symmetrical dicyclohexanocucurbit [6]uril (1,4-DiCyHQ [6]), and percyclohexanocucurbit [6]uril (CyH6Q [6]), as well as the supramolecular assemblies formed with the aid of inorganic anions (NO3− and Cl−) as structure-directing agents. Single-crystal X-ray diffraction analysis has revealed that the interaction results in the formation of three kinds of coordination complexes. The main driving forces may be the ion-dipole interaction of inorganic anions and the electropositive outer surface of Q[n].

Two new twisted cucurbiturils, cucurbit[13]uril (tQ[13]) and cucurbit[15]uril (tQ[15]), have been synthesized and separated, and their structures have been confirmed by NMR spectroscopy and MALDI-TOF mass spectrometry together with the X-ray structures of two new complexes, {Dy(H2O)4Cd(H2O)4tQ[13]}·2.5[CdCl4]·65H2O and {Cd0.5(H2O)2tQ[15]}·[CdCl4]·47H2O. tQ[15] is the largest cucurbit[n]uril (Q[n]) in the Q[n] family reported to date. The X-ray diffraction studies of both complexes indicated that these large tQ[n]s effectively exhibit two different cavities-a central cavity and two side cavities. Preliminary host-guest behavior by each of the new systems was investigated by NMR studies.

Coordination of lanthanide cations (Ln3+) and a symmetrical dicyclohexanocucurbit[6]uril (1,4-DiCyHQ[6]) in the presence of tetrachlorozincate was investigated. X-ray single crystal diffraction analysis revealed that with [ZnCl4]2− anions as a structure directing agent, the interaction of lighter lanthanide cations and 1,4-DiCyHQ[6] results in the formation of fast precipitation, whereas the interaction of heavier lanthanide cations and 1,4-DiCyHQ[6] results in solid crystals. This provides a potential strategy for separating lighter and heavier lanthanide cations.

Molecular interactions between an inverted cucurbit[6]uril (iQ[6]) with α,ω-alkyldiammonium guests (H3N(CH2)xNH3Cl2, x = 2, 4, 6, 8, 10, and 12 named 1–6) were investigated in aqueous and acidic solutions by various techniques. 1H NMR spectroscopy revealed that only compounds 3 and 4 underwent an equilibrium interaction with the iQ[6] host, with association constants in acidic solution of ~83 and ~41 L mol−1, respectively, while the other guests showed no obvious interaction. Only two host–guest interaction systems gave rise to single crystals in the presence of polychloride transition metal anions as structure-directing agents. X-ray diffraction revealed that guests 1 and 3 interacted with iQ[6] through portal and cavity interactions, respectively.

Two Q[n]-based porous compounds, Q[5]·[PtCl6]2 −·2H3O·12H2O and 2Q[8]·[PtCl6]2 −·2H3O·74H2O in cooperating the hexachloroplatinate(IV) anion ([PtCl6]2 −) as an inorganic structure directing agent are demonstrated. The driving forces for the formation of such novel Q[n]-based porous compounds are considered to be the outer surface interactions of Q[n]s, including dipole interactions between Q[n]s and ion-dipole interactions between [PtCl6]2 − anions and Q[n]s. Moreover, the Q[5]-based porous compound displays absorption distinctness for tetrachloromethane, whereas the Q[8]-based porous compound displays absorption distinctness for methanol.

Coordination of fully substituted cyclopentano cucurbit[5]uril (CyP5Q[5]) with an alkali cation (A+) in the presence of tetrachloridezicate anions was investigated. Single-crystal X-ray diffraction analysis revealed that the CyP5Q[5]–Na+ and K+–[ZnCl4]2−–HCl interaction systems yielded an A+/Cl−@CyP5Q[5]/A+-type molecular capsule, and that a chloride anion was included in the cavity of the CyP5Q[5] molecule. [ZnCl4]2− anions were not involved in direct coordination with the A+/Cl−@CyP5Q[5]/A+ capsule. The CyP5Q[5]–Rb+ and Cs+–[ZnCl4]2−–HCl interaction systems yielded an A+/CyP5Q[5]/A+-type molecular capsule shell, and no chloride anions were included in the cavity of the CyP5Q[5] molecule. [ZnCl4]2− anions directly interacted with coordinated Rb+ or Cs+ cations through electrostatic interaction, and [ZnCl4]2− anions in particular played the role of linkers, resulting in the formation of a linear supramolecular assembly ⋯[ZnCl4]2−–A+/Cl−@CyP5Q[5]/A+–[ZnCl4]2−–A+/Cl−@CyP5Q[5]/A+⋯. Close inspection revealed that the obtained CyP5Q[5]/A+-based supramolecular assemblies (A = Na, K, Rb, Cs) presented different porous conformation and could show different absorption properties.