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A new and innovative fluorescent structure was constructed on Cyclotriveratrylene affiliated to Dansyl chloride (DNSC) and was used to detect Cr (III) and Fe (III) among the various cations by using spectrofluorimetric method. The characterization of the new compound was carried out using the 1H-NMR, 13C-NMR, and ESI–MS techniques. The interaction and role of DNSC-CTV with cations was reviewed. A change in the spectra of absorption directed to the conclusion that there is substantial interaction of Cr (III) and Fe (III) with DNSC-CTV. Furthermore the interaction of the ligand DNSC-CTV with the metal ions Chromium (III) and Iron (III) showed quenching in the emission spectra. Quantum yield of the complexes were calculated and the stern volmer analysis was done to deduce the quenching mechanism of fluorescence to being either static or dynamic. The molecule DNSC-CTV was further studied with the help of computational methods such as molecular docking to study the binding interactions and properties of the molecule.

New photoswitchable pyridyl-azo-phenyl-decorated tripodal host ligands (Laz) that belong to the cyclotriveratrylene family have been synthesized, and their photoswitching behavior and crystal structures determined. The latter includes a remarkable 7-fold Borromean-weave entanglement of π-π stacked layers. Trigonal bipyramidal {[Pd(en)]3(Laz)2}6+ metallo-cryptophanes (en = ethylenediamine) were formed from these and a previously known pyridyl-azo-phenyl-decorated tripodal host ligand. These coordination cages dissociate at low concentrations and are less robust to photoswitching of the Laz ligands than were previously reported Ir(III)-linked metallo-cryptophanes with similar ligands, reflecting the greater lability of the Pd-N bonds. The {[Pd(en)]3(Laz)2}6+ cages all act as hosts, binding octyl sulfate anions, or N-[2-(dimethylamino)ethyl]-1,8-naphthalimide in a dimethyl sulfoxide solution.

The synthesis of four fluorescent diastereoisomeric molecular cages containing cyclotriveratrylene and sucrose moieties connected via the naphthalene linkers is reported. These diastereoisomers were found to be selective and efficient receptors for acetylcholine and choline. Compound P-5a has a better affinity for choline over acetylcholine, while cage M-5a exhibits a higher association constant for acetylcholine over choline. The highest selectivity value was observed for compound M-5a (KACh/KCh = 3.1). Cages P-5a, P-5b, M-5a, and M-5b were fully characterized by the advanced NMR techniques, and ECD spectroscopy was supported by DFT calculations. The binding constants Ka of these receptors were determined by fluorescence titration experiments in acetonitrile.

International audience; The key features that govern the chirality transfer in a structurally contracted covalent cage, consisting of a northern chiral cyclotriveratrylene (CTV) connected to a southern tris(2-pyridyl-methyl)amine (TPA) unit by three methyl bridges, are described. The preferential orientation of the propeller arrangement of TPA is dictated by its compact structure, with an arm of the TPA unit pointing inside the cage, together with the relative positioning of the three pyridines regarding the chiral CTV cap. The diastereomers with P/P (or M/M) configurations for the CTV and TPA units adopt eclipsed structures and were found to be more stable by 40 kJ mol À1 than the P/M (or M/P) diastereomer which displays a staggered arrangement. The existence of isomerization pathways between isomers of the cage with low energy barriers (38 kJ mol À1) accounts for the 1 H-NMR signal, which is consistent with an averaged C 3 structure.

Cyclotricatechylene (ctcH6 ) is a bowl-shaped macrocyclic compound that can be used as a building block for self-assembled capsules. ctcH6 and its derivatives in various protonation states - here collectively labeled as CTC - form dimers that resemble the shape of a clam. These clam-shaped entities have been studied experimentally by Abrahams, Robson, and co-workers [B. F. Abrahams, N. J. FitzGerald, T. A. Hudson, R. Robson and T. Waters, Angew. Chem. Int. Ed. 2009, 48, 3129-3132] where the capsules acted as an excellent host for large alkali-metal cations. In this study, we present a detailed analysis based on accurate dispersion-corrected Density Functional Theory approaches that reveals the factors that stabilise such CTC-based capsules at different protonation states and their interaction with various encapsulated guests. Our results show that the capsules' overall stability results as an interplay of hydrogen bonding, London dispersion, and electrostatic effects. The most stable capsules with group-1 and group-2 cations as guests contain only six phenolic hydrogens, as opposed to the maximum possible number of twelve. Inclusion of larger alkali-metal cations is favoured due to larger London-dispersion contributions. Cations are favoured as guests over isoelectronic neutral species, as the resulting host-guest complexes experience additional stability due to cooperative effects. In fact, using the latter to drive the formation of specific capsules could be used in future strategies aimed at synthesising similar aggregates; our results provide an insightful understanding and useful guidance for such future endeavours.

In order to study various environmental pollutants among the class of nitro aromatic compounds, a new and novel sensor derived from a cyclotriveratrylene derivative has been developed which rapidly detects 4-nitrophenol from among the class of nitro aromatic compounds via spectrofluorimetric method. The newly derrivaritized cyclotriveratrylene compound is successfully confirmed by using the available techniques of 1H NMR, 13C NMR and ESI-MS. The newly developed molecule was named 4C7NbF-CTV. The complexation behaviour of 4C7NbF-CTV with various nitro aromatic compounds was studied. In the absorption spectra a shift was observed, which indicated that 4-nitrophenol interact with 4C7NbF-CTV. An enhanced intensity of fluorescence of 4C7NbF-CTV was observed on adding 4-nitrophenol.

International audience; A new off-on fluorescent hemicryptophane probe for acetylcholine has been designed. This hemicryptophane, made fluorescent via an extension of the conjugation of its cyclotriveratrylene C3-symmetry part, exhibits improved fluorescence properties compared with fluorescent hemicryptophanes previously described. Indeed, both the excitation and emission wavelengths are red-shifted and the quantum yield is increased. Moreover, this hemicryptophane is able to bind acetylcholine with a high association constant of 3.2 × 104 M-1. This recognition process is accompanied by an increase in the brightness of the capsule. Surprisingly, contrary to what is commonly observed with cyclotriveratrylene-based hosts, the quaternary ammonium of the guest interacts with the tris(2-aminoethyl)amine south part of the hemicryptophane instead of the cyclotriveratrylene north part. This unusual binding mode is supported by both proton NMR experiments and density functional theory calculations.

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Cyclotriveratrylene (CTV) is a C3-symmetrical macrocycle, which can be used as a chiral building block in the construction of supramolecular containers. Coupling of the CTV unit with a sucrose mole...

C3-functionalized cyclotriguaiacylene (CTG) derivatives were employed in the development of highly selective recognition compounds due to their unique molecular structures. Here, a novel C3-functionalized CTG containing boronate (PPB-CTG) was synthesized and its molecular recognition ability for hydroxyanthraquinones was investigated by fluorescence spectroscopy. The addition of the synthesized PPB-CTG led to a large increase in the fluorescence intensity of only alizarin and not 1-hydroxyanthraquinone, 2-hydroxyanthraquinone nor quinizarin. It was, thus, suggested that the cyclotriveratrylene (CTV) structure plays an important role in the recognition ability toward alizarin since the mono-phenyl boronate compound (m-TPBAP) showed poor fluorescence properties toward alizarin. Moreover, it was found that the 1:1 mixture of PPB-CTG and alizarin was effective as a fluorescence-enhanced probe toward fluoride ions.

The trinuclear complexes [{PdI2(pyCl)}3(L1)] C1 and [{PdI2(pyCl)}3(L2)] C2, where pyCl = 3-chloropyridine, L1 = methyl(cyclotriguaiacylenyl)methylbenzimidazol-2-ylidene and L2 = benzyl(cyclotriguaiacylenyl)methylbenzimidazol-2-ylidene, each feature three palladium N-heterocyclic carbene (NHC) centres tethered onto a host-type cyclotriguaiacylene scaffold. Crystal structures of different solvates of complex C1 reveal different host-guest motifs including intra-cavity binding of dioxane guests concomitant with intramolecular halogen bonding interactions of C1. Mononuclear NHC analogues of C1 and C2, namely [PdI2(pyCl)(L3)] C3 and [PdI2(pyCl)(L4)] C4, where L3 = (3-chloropyridyl)-1-(2-methoxyphenyoxy)methyl-3-methylbenzimidazol-2-ylidene and L4 = (3-chloropyridyl)-1-(2-methoxyphenyoxy)methyl-3-benzylbenzimidazol-2-ylidene, were also synthesised and their crystal structures determined. Complexes C1-C4 are competent catalysts for Suzuki Miyaura cross-coupling, and interestingly exhibit a switch in the normal regioselectivity observed for reactions of 2,4-dibromopyridine with aryl boronic acids, usually C2-selective, yielding C4-arylated product preferentially over C2-arylated product.

C 3-Substituted cyclotriveratrylene (CTV) derivatives were considered suitable candidates for recognition compounds due to their unique structures. In this study, a C3-substituted CTV derivative with three fluorogenic 8-quinolinyl groups (1) was designed and prepared as a fluorescent probe. The synthesized CTV derivative 1 exhibited a selective response of fluorescence enhancement toward Cu2+ ions among the examined cations. The sensing ability of CTV derivative 1 toward Cu2+ ions was superior to that of the previously reported C3-substituted CTV derivative with three 2-quinolinyl groups (2). It is, thus, suggested that the CTV structure plays an important role in selective sensing ability toward Cu2+ ions since the mono-quinoline compound 5 showed fluorescence properties toward the Cr3+, Fe2+ and Fe3+ ions in addition to Cu2+ ions. In other words, the high Cu2+ ion-selectivity of CTV derivative 1 was demonstrated even in the presence of other co-existing examined cations. Moreover, it was found that CTV derivative 1 could work as a reversible fluorescence-enhanced probe toward Cu2+ ions by the simple addition of Et3N.

A crown-shaped cyclotriveratrylene (CTV) analogue with persubstituted arene units-namely, cyclotrixylohydroquinoylene (CTX)-was synthesized from tetrasubstituted o-xylohydroquinone. Importantly, a series of CTX derivatives were prepared by introducing second bridged methylene, phenylphosphine oxide, and dimethylsilyl at the middle rim, referred to as CTX[CH2], CTX[P(O)Ph], and CTX[SiMe2], respectively, with the completely locked crown conformation, leading to the formation of unique C3-symmetric Chinese censer-shaped pocket structures. In addition, the water-soluble CTX[CH2] derivative (WCTX[CH2]) was synthesized from CTX[CH2] by simple oxidation reaction with the modification at the upper rim, and its host-guest interaction with methyl viologen in water was investigated.

In this paper, a modified Cyclotriveratrylene was synthesized and linked to a branched Polyethylenimine, and this unique polymeric material was subsequently examined as a potential supramolecular carrier for Doxorubicin. Spectroscopic analysis in different solvents had shown that Doxorubicin was coordinated within the hollow-shaped unit of the armed Cyclotriveratrylene, and the nature of the host&ndash, guest complex revealed intrinsic Van der Waals interactions and hydrogen bonding between the host and guest. The strongest interaction was detected in water because of the hydrophobic effect shared between the aromatic groups of the Doxorubicin and Cyclotriveratrylene unit. Density functional theory calculations had also confirmed that in the most stable coordination of Doxorubicin with the cross-linked polymer, the aromatic rings of the Doxorubicin were localized toward the Cyclotriveratrylene core, while its aliphatic chains aligned closer with amino groups, thus forming a compact supramolecular assembly that may confer a shielding effect on Doxorubicin. These observations had emphasized the importance of supramolecular considerations when designing a novel drug delivery platform.

International audience; The design and the characterization of supramolecular additives to control the chain length of benzene-1,3,5-tricarboxamide (BTA) cooperative supramolecular polymers under thermodynamic equilibrium is unraveled. These additives act as chain cappers of supramolecular polymers and feature one face as reactive as the BTA discotic to interact strongly with the polymer end, whereas the other face is nonreactive and therefore impedes further polymerization. Such a design requires fine tuning of the conformational preorganization of the amides and the steric hindrance of the motif. The chain cappers studied are monotopic derivatives of BTA, modified by partial N-methylation of the amides or by positioning of a bulky cyclotriveratrylene cage on one face of the BTA unit. This study not only clarifies the interplay between structural variations and supramolecular interactions, but it also highlights the necessity to combine orthogonal characterization methods, spectroscopy and light scattering, to elucidate the structures and compositions of supramolecular systems.

The scope of the trimerisation reaction of 3-substituted benzyl alcohols was explored. Several C 3 -symmetric cyclotribenzylene derivatives were obtained in preparative useful yields in one step and applied to the short synthesis (one or two steps) of two CTB derivatives, so far only accessible in six or seven linear steps.

Series of novel CTV derivatives with one, two and three triphenylene units were designed and synthesized via click reaction in 72–84% yields. The influences of the numbers of triphenylene units on mesomorphic behaviors were investigated. The results suggested that one triphenylene unit could not counteract the rigidity of CTV skeleton, resulting in no mesophase for CTV derivative 6 with one triphenylene unit. The strong induction of more triphenylene units leaded to the mesophase for CTV derivative 7 with two triphenylene units and 8 with three triphenylene units. The more triphenylene units decreased the phase transition temperatures. The XRD analysis suggested that compound 8 possessed higher ordered hexagonal columnar mesophase than compound 7, implying that the more triphenylene units were favorable for improving the structural symmetry and produced the ordered columnar stacking. Compound 8 was the first example of high ordered hexagonal columnar liquid crystalline molecule based on CTV skeleton.

The hexapodal ligand hexakis(isonicotinoyl)cyclotricatechylene (L1) belonging to the cyclotriveratrylene family of host-molecules has been synthesised and used in the assembly of a series of coordination polymer materials with Re(I), Co(II), Cu(II), Ni(II) and Ag(I) salts. Single crystal structures of the coordination polymers [Re3(L1)2Br3(CO)3] 1, and an isomorphic [M3L2] series where M = Co, Cu or Ni, reveal 2D framework structures with a simplified topology of 36 or hxl. These are composed of M6(L1)2 metallo-cages linked together in a pair-wise fashion through each metal centre. Compound 1 is a rare example of a rhenium coordination polymer and was investigated for guest uptake from solution, complexing I2. The mixed-ligand species [Cu2(L1)(CF3CO2)3(isonicotinate)] forms a (3,4,5)-connected 2D coordination polymer, while [Ag2(L1)(DMF)2]·2BF4·2(H2O)·6(DMF) features a 2D network of (3,6)-connectivity and with kagome dual (kgd) topology.

By using a novel imidazole-functional cyclotriveratrylene ligand, two isostructural frameworks, [Cd3(HECTV)(bdc)3]·DMF·6H2O (1) and [Zn3(HECTV)(OH-bdc)3]·3DMF·4H2O (2) (HECTV = 5,6,12,13,19,20-hexaimidazolium-ethoxy-cyclotriveratrylene), were constructed. The two compounds exhibit fascinating 4-fold interpenetration three-dimensional frameworks. There are still large void spaces in the structures despite the interpenetration, which were filled with solvent molecules. Interestingly, 1 demonstrates a single-crystal to single-crystal transformation with the guests changed by a cycloalkane solvent. Strikingly, 1 and 2 feature highly heterogeneous catalytic activities for Knoevenagel condensation and CO2 cycloaddition, respectively. In particular, catalysts 1 and 2 could be reused with good catalytic performance.

The chiral self-sorting process during the self-assembly of homochiral Pd6L8 capsules from cyclotriveratrylene (CTV)-based chiral tritopic ligands (L) and (Py*: 3-chloropyridine) was investigated by an NMR-based approach (QASAP: quantitative analysis of the self-assembly process). From the beginning to the formation of the immature capsules (ICs), enantiomeric ligands are distributed in the intermediates in a non-self-sorting manner, which leads to the isomers of heterochiral ICs over 99% yield. The mismatch of the chirality in the heterochiral ICs prevents intramolecular ligand exchanges in ICs to form the heterochiral capsules. The correction of the chirality in the heterochiral ICs (chiral self-sorting) takes place very slowly to finally lead to the homochiral capsules. The reason why the chiral self-sorting took place in the late stage of the self-assembly (after the formation of the heterochiral ICs) would be due to the relatively high flexibility of the CTV-based ligand.

A straightforward and practical access to various C1-symmetric cyclotriveratrylene derivatives from a monohalogenated cyclotriphenolene is described. This unique scaffold can also be used as a precursor for the rapid construction of monofunctionalizable cryptophane-based biosensors for hyperpolarized 129Xe MRI.

International audience; In the wide area of host−guest chemistry, hemicryptophanes, combining a cyclotribenzylene (or cyclotriveratrylene CTV) unit with another different C 3-symmetrical moiety, appears as a recent family of molecular cages. The synthesis and recognition properties of the first hemicryptophane were reported in 1982 by Collet and Lehn, but the very little attention received by this class of host compounds in the 20 years following this first promising result can account for their apparent novelty. Indeed, in the last 10 years hemicryptophanes have aroused growing interest, and new aspects have been developed. Thanks to the rigid shaping unit of the north part (CTV) and also the variable and easily functionalized south moiety, hemicryptophanes are revealed to be inherently chiral ditopic host compounds, able to encapsulate various guests, including charged and neutral species. They also enter the field of stimuli-responsive supramolecular systems exhibiting controlled functions. Moreover, endohedral functionalization of their inner cavity leads to supramolecular catalysts. The confinement of the catalytic center affords nanoreactors with improved catalytic activities or selectivities when compared to model systems without a cavity. The current trend shows that reactions in the confined space of synthetic hosts, mimicking enzyme behavior, will expand rapidly in the near future.

The preparative resolution of a trifunctionalized C3-symmetrical chiral cyclotriveratrylene derivative was achieved via high-performance liquid chromatography (HPLC) on a chiral stationary phase. This approach is a promising alternative to the previously reported resolution through formation of diastereomeric esters because it involves fewer synthetic steps and is less prone to thermal (re)racemization. During these studies an intermediate saddle conformer could also be isolated and characterized by 1H and 13C NMR spectroscopy. The HPLC separation method was further developed in order to allow investigations on the racemization behavior of the cyclotriveratrylene derivative.

Hemicryptophanes have recently emerged as an attractive class of cages due to their interesting applications as supramolecular receptors and catalysts. Over the last decade, substantial advances have been made regarding the preparation of enantiopure versions of these synthetic receptors. Enantiopure hemicryptophanes are commonly obtained through the separation of diastereomers by chromatography, or by resolution of racemic mixtures using chiral HPLC. This short review summarizes the existing methods to access to these chiral organic architectures and discusses the benefits and drawbacks of each approach.1 Introduction2 Enantiopure Hemicryptophanes Obtained by Introducing Additional Chiral Units and Separation of Diastereomers2.1 Synthesis by Means of Intramolecular Macrocyclization Reactions2.2 [1+1] Coupling of the CTV and the Southern Part3 Enantiopure Hemicryptophanes Obtained by Means of Chiral HPLC Resolution of Enantiomers3.1 Resolution of Hemicryptophane Racemates3.2 Resolution of CTV-Based Precursor Racemates4 Conclusion

International audience; The five-steps synthesis of a hemicryptophane cage combining a benzene-1,3,5-tricarboxamide unit and a cyclotriveratrylene (CTV) moiety is described. Chiral high-performance liquid chromatography (HPLC) was used to resolve the racemic mixture. The absolute configuration of the isolated enantiomers was assigned by comparison of the experimental electronic circular dichroism (ECD) spectra with the calculated ones. X-ray molecular structures reveal that the capped benzene-1,3,5-tricarboxamide unit adopts a structurally chiral conformation in solid state: the chirality of CTV moiety controls the Λ or Δ orientation of the three amides.

International audience; Cyclotriveratrylene (CTV) is a macrocyclic cyclophane presenting a bowl-shaped conformation, used as building block to construct cryptophane and hemi-cryptophane capsules. A method to synthesize new enantiopure CTV derivatives with an unprecedented spatial arrangement of their substituents, exhibiting C 1 symmetry, is described. The absolute configuration was assigned by ECD spectroscopy coupled with modeling. A statistical model has allowed for optimization of the proportion of C 1 CTV, and the modularity of this approach is also highlighted.

Pyramidal molecular hosts related to cyclotriveratrylene (CTV) form self-assembled cages including organic cages, hydrogen-bonded cages, and metallocages. The latter include M3L2, M4L4, M6L8, and M12L8 assemblies, including topologically complicated structures. Metallocages may show ligand exchange and/or homochiral sorting of the C3-symmetric CTV-analog ligands. Cages also occur within coordination networks.

Hemicryptophanes have been designed to include endohedral functionalities in the cavity, giving molecular receptors and catalysts. In this study, a tri-aromatic amide hemicryptophane was synthesized. The host–guest interactions with various types of tetraalkylammonium salts were investigated. The structure of the partial inclusion complex in which an acetylcholine molecule was encapsulated within the hemicryptophane was characterized by NMR, X-ray crystal structure, and ESI-MS analysis.

International audience; The design of multivalent glycoconjugates has been largely studied using a variety of core scaffolds. Cyclotriveratrylenes (CTV) have been scarcely used in this context. The synthesis of the tri- and hexa-propargylated CTV cores allowed the prepn. of the corresponding glycoclusters with galactose or fucose residues through azide-alkyne "click" chem. Their interactions with bacterial lectins (LecA, LecB and BambL) was confirmed and studied by titrn. microcalorimetry. Adsorption onto carbon nanotubes was then attempted based on the hydrophobic CTV cores. Their incorporation into field effect transistor (FET) devices was accomplished but the data collected largely suggested a poor interaction of CTV-based glycoclusters with the carbon nanotubes leading to non-specific detection of the lectins.

Size-complementary cyclotriveratrylene (CTV)-based hosts can incarcerate C76, C78, and C84, thus allowing the selective isolation of these higher-order fullerenes from a commercially available mixture of fullerenes. The hemicarceplexes, formed after the encapsulation of the size-complementary fullerenes within the hosts, are isolated by column chromatography and released at elevated temperature, thereby leading to the isolation of C76/C78 and C84 in good purities (up to 95 and 88 %, respectively).

A cyclotriveratrelyne–acetonitrile inclusion complex is shown to undergo a single-crystal-to-single-crystal transformation upon desolvation to an intermediate phase and it is furthermore demonstrated that the preparation conditions may introduce polymorphism of the apohost. We characterised the as-synthesized and desolvated polymorphs using single crystal (polymorph 1) and powder X-ray diffraction, thermal analysis and gas sorption. Successive data collections on the as-synthesized crystal at 50 °C show that the rotation of a single, unique methoxy group of the host molecule may allow evacuation of solvent molecules from the seemingly non-porous crystal.

International audience; A new chiral hemicryptophane cage combining an electron-rich cyclotriveratrylene (CTV) unit and polar amine functions has been synthesized. The resolution of the racemic mixture has been performed by chiral HPLC, and the assignment of the absolute configuration of the two enantiomers has been achieved using ECD spectroscopy. In contrast with other hemicryptophane receptors, the two enantiomeric hosts display both remarkable enantioselectivities in the recognition of carbohydrates and good binding constants. Moreover, by switching the chirality of the CTV unit from M to P, a strong preference shift from glucose to mannose derivatives is observed.

Series of cyclotriveratrylene (CTV) derivatives with triazole ring and three alkyl groups were prepared by one-pot click condensation in yield of 80–88%. The structures and crown conformations were confirmed by NMR and MS. Their liquid crystalline properties were investigated by DSC, POM and XRD analysis. The studies on mesomorphic properties suggested that the CTV derivatives with pentyl, hexyl or dodecyl groups show no mesophase but the one with octadecyl groups possesses ordered hexagonal columnar mesophase. In comparison with the reported columnar CTV liquid crystals with six alkyl chains at least, the CTV columnar CTV liquid crystal with three alkyl chains was reported for the first time. These results suggested a subtle balance between the number and length of alkyl chains for columnar CTV liquid crystalline behavior.

A series of C3-symmetric triiodocyclotriveratrylene (CTV-I3) derivatives have been successfully arylated to afford the corresponding triarylcyclotriveratrylene derivatives in high yields by using triarylbismuth compounds as threefold coupling reagents under palladium-catalyzed conditions. This functionalization is valuable in the context of the development of new synthetic and coupling studies to rapidly access cyclotriveratrylene molecular skeletons with rigid and deeper cavities.

Cyclotriveratrylene-oxime (CTV-oxime) derivatives that terminate with a dithiolate linker were synthesized enabling the supramolecular scaffold to adhere to gold nanoparticles (AuNPs) with the bowl-shaped cavity of the CTV scaffold exposed for utilization in host–guest chemistry. Exposure of these CTV functionalized AuNPs to varying concentrations of di- and trivalent metal cations resulted in the formation of large CTV-AuNP polymeric clusters and an accompanying a shift in the plasmon resonance. These interactions between the CTV-AuNPs and the metal cations in solution provides proof-of-concept that supramolecular functionalized AuNPs can be used as a simple and straightforward, on-site detection system for toxic metal cations in solution. The order of binding affinity of the metals studied based on observed K d values is Cu 2+ > Zn 2+ > Pb 2+ > Hg 2+ > Eu 3+ > Cd 2+ .

Cyclotriveratrylene (CTV) is reported here for the first time as stationary phase for capillary gas chromatographic (GC) separations. CTV stationary phase showed weak polarity comparable to the conventional 5% phenyl polysiloxane stationary phase but exhibited different retention behaviours and higher resolution for some of the indicated analytes. Most importantly, CTV stationary phase exhibited preferential selectivity for halogenated compounds, positional and geometrical isomers. Effect of column temperature on retention and thermal stability of CTV column were also investigated. Moreover, CTV capillary column showed good repeatability in terms of run-to-run, day-to-day and column-to-column. The unique physicochemical features and efficient separation ability for analytes of close properties show the potential of CTV as a new-type stationary phase in GC as well as separation science.

Five organic complexes are prepared by cocrystallization of tri-[(N-methyl-2-imidazoly)methoxy]cyclotriguiacylene (TMIM-CTG) with corresponding acids. While hydrogen bonds are the basic interactions in the five complexes, the homo-included motifs with C-H center dot center dot center dot pi interactions also control the molecular arrangement except for complex 5. In complex 1, the two dimensional networks contain 1D zigzag chains formed by hydrogen bonding and 1D chains of homo-included CTG motifs. Complex 2 has 2D 4 center dot 8(2) hydrogen bonding networks, and the chains of homomeric inclusion extend the 2D structure to a 3D framework. Complex 3 contains four-membered rings through hydrogen bonds, and the chains of homo-inclusion link the rings to a novel 2D network. In complex 4, hydrogen bonds construct a novel double-layer 2D network, which is extended to a 3D framework by "hand-shake" dimeric homomeric inclusion interactions. Interestingly, there is no homomeric inclusion phenomenon in complex 5 and hydrogen bonds solely connect two components to a chiral (6,3) 2D network.

A fast and facile method for captopril determination is reported using an electrode modified to contain the precursor of a species which can selectively and suitably detect the target. Cyclotriveratrylene (CTV) is first incorporated into a carbon paste electrode then the precursor is converted into cyclotricatechylene (CTC) using voltammetric methods at the point in time when the captopril detection is sought. The resulting cyclotricatechylene (CTC) was used to mediate the electrochemical detection of the thiol containing drug, captopril, via electrocatalytic oxidation. Optimization towards the detection method was investigated by changing experimental conditions including pH and mediator loading. Optimal analytical parameters were determined in acidic conditions which gave a real measurable limit of detection of 1 µM for captopril detection.

A review of the emerging field of cyclotriveratrylene-derived coordination cages is presented. Ligand-functionalised cyclotriveratrylene (CTV) derivatives self-assemble with a range of metal cations to afford coordination cages, polymers and topologically non-trivial constructs, such as [2]catenanes and a self-entangled cube. Increased control over their self-assembly allows for the controlled and predictable formation of well-defined coordination cages for application in host-guest and recognition chemistry, with surfactant binding and single-crystal-to-single-crystal (SCTSC) uptake of small-molecule guests being observed.

The synthesis of a semi-orthogonally protected CycloTriVeratrilene (CTV) scaffold derivative as well as the sequential introduction of three different peptide loops onto this molecular scaffold via Cu(I)-catalyzed azide alkyne cycloaddition towards a medium-sized protein mimic is described. This approach for the construction of medium-sized protein mimics is illustrated by the synthesis of a paratope mimic of the monoclonal antibody Infliximab (Remicade®) and provides access to a range of highly pre-organized molecular constructs bearing three different peptide segments. This approach may find wide applications for development of protein-protein interaction disruptors as well as synthetic vaccines.

International audience; The synthesis, characterization, and chiroptical properties of a new class of hemicryptophane cages combining a cyclotriveratrylene unit and a tris(2-pyridylmethyl)amine (TPA) moiety are reported. Changing the linkers between these two units allows for the modification of the size and shape of the cavity. The synthesis is straightforward and efficient, providing gram-scale of cage compounds. The racemic mixture of each hemicryptophane host can be readily resolved by chiral HPLC, giving an easy access to the enantiopure molecular cages of which absolute configurations have been assigned by ECD spectroscopy. These new hemicryptophanes are available chemical platforms ready to use for various purposes due to the versatile metal complexation properties of the TPA unit. A Zn(II)@hemicryptophane complex has been obtained and used as a heteroditopic host for the selective recognition of zwitterionic guests.

International audience; Five sets of oxido-vanadium(V) complexes, which include both cages and open structures, were prepared and tested in the catalytic oxidation of sulfides. It was found that the hemicryptophane complexes, which are simultaneously comprised of cyclotriveratrylene (CTV), binaphthol and oxido-vanadium(V) moieties, are the most efficient supramolecular catalysts. The specific shape of the confined hydrophobic space above the metal center leads to a strong improvement in the yield, selectivity and rate of the reaction, compared to the other catalysts investigated herein. A remarkable turnover number (TON) of 10 000 was obtained, which can be attributed to both the high reactivity and stability of the catalyst. Similarly to enzymes, the kinetic analysis shows that the mechanism of oxidation with the supramolecular catalysts obeys the Michaelis–Menten model, in which initial rate saturation occurs upon an increase in substrate concentration. This enzyme-like behavior is also supported by the competitive inhibition and substrate size-selectivity observed, which underline the crucial role played by the cavity.

This article focuses on the use of calixarenes, resorcinarene-based cavitands, and other related molecules as topologically directing platforms for the assembly of large, predominantly metal-directed supramolecular capsule assemblies; some examples involving the related building block cyclotriveratrylene are also covered, but to a lesser extent. We also highlight both noncovalent and metal-directed systems constructed from alternative ligands in order to introduce associated assembly strategies that have been applied to the building blocks highlighted here. Finally, we have also included some assemblies that lie between areas covered in separate volumes in this reference work, but that relate to the main theme of this chapter.

Trigonal bipyramidal metallo-cage species [Pd3(dppp)3(L)2]∙6OTf (where dppp = bis(diphenylphosphino)propane, OTf = triflate and L is tris(iso-nicotinoyl)cyclotriguaiacylene (L1) or tris(fluoro-iso-nicotinoyl)cyclotriguaiacylene (FL1)) have been characterised in solution to exist predominantly as the anti-isomers. The crystal structure of [Pd3(dppp)3(FL1)2]∙6OTf, however, was found to be the achiral syn-isomer. The complex [Pd3Cl3(L2)2] (where L2 = tris(methylbenzimidazolyl)cyclotriguaiacylene) is a trans-linked M3L2 cage, observed by mass spectrometry and in the solid state as the anti-isomer. Ligand L2 also forms a 1:1 co-crystal with cyclotriguaiacylene.

Although interest in cyclotriveratrylene and its analogues has been significant, limitations in the ability to adjust its structure fully have hampered studies into their complete range of properties. A unique strategy to synthesize a previously unobtainable cyclotriveratrylene analogue and a procedure which adjusts the inner methylene bridges of that material to a triketone is reported. A second triketone synthesis and computational studies indicate the parameters needed for success.

C1-symmetric cyclotriveratrylene analogues 2–8 with various functional groups at one benzene moiety were prepared starting from the selectively demethylated compound 1. Through the chemical resolution, a pair of enantiomers of C1-symmeric compound 1 could be separated with gram scale. Compound 8, which possessed an N-linked imidazolium unit at the upper rim of the macrocyclic skeleton through a methylene linker, was successfully applied to 1,4-Michael addition reaction of alcohol to unsaturated aryl ketone. Its supramolecular catalytic activity as an NHC precursor was demonstrated by the chem-selectivity to aromatic alcohol than alkyl alcohol.