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The title compound, C47H60O6·3CHCl3, is the first example of a lower-rim mono-ester calixarene derivative to be crystal- lographically characterized. The cone conformation adopted by the macrocycle is stabilized by three intramolecular hydrogen bonds. Self-inclusion of the methyl ester chain in the cavity of an adjacent molecule gives rise to infinite chains parallel to the c axis. C—H…π interactions involving the methyl group most imbedded in the cavity contribute to the stabilization of the system. [ABSTRACT FROM AUTHOR]

Invited for the cover of this issue are the group of Iwona and Jean-François Nierengarten from the University of Strasbourg (LIMA, UMR 7042, CNRS) and collaborators from the University of Carthage and the IPHC (University of Strasbourg and CNRS, UMR 7178). The image illustrates the fast motions of a pillar[5]arene subunit along the axle of a rotaxane, reminiscent of those of a guitarist's hand along the neck allowing him to use random parts of a scale with certain sweet spots when improvising a solo. Read the full text of the article at 10.1002/chem.202304131., (© 2024 Wiley-VCH GmbH.)

Invited for the cover of this issue are the group of Iwona and Jean-François Nierengarten from the University of Strasbourg (LIMA, UMR 7042, CNRS) and collaborators from the University of Carthage. The image depicts a sky of umbrellas floating in the air to illustrate the protective effect allowing the efficient mono-acylation of a symmetrical rotaxane building block with two pentafluorophenyl ester stoppers. Read the full text of the article at 10.1002/chem.2023003501., (© 2024 Wiley-VCH GmbH.)

Glycan-protein interactions control numerous biological events from cell-cell recognition and signaling to pathogen host cell attachment for infections. To infect cells, some viruses bind to immune cells with the help of DC-SIGN (dendritic cell [DC]-specific ICAM3-grabbing nonintegrin) C-type lectin expressed on dendritic and macrophage cell membranes, via their envelope protein. Prevention of this infectious interaction is a serious therapeutic option. Here, we describe the synthesis of the first water-soluble tetravalent fucocluster pseudopeptide-based 1,3-alternate thiacalixarenes as viral antigen mimics designed for the inhibition of DC-SIGN, to prevent viral particle uptake. Their preparation exploits straightforward convergent strategies involving one-pot Ugi four-component (Ugi-4CR) and azido-alkyne click chemistry reactions as key steps. Surface plasmon resonance showed strong inhibition of DC-SIGN interaction properties by tetravalent ligands designed with high relative potencies and β avidity factors. All ligands block DC-SIGN active sites at nanomolar IC 50 preventing cis-cell infection by Ebola viral particles pseudotyped with EBOV glycoprotein (Zaire species of Ebola virus) on Jurkat cells that express DC-SIGN. In addition, we observed strong inhibition of DC-SIGN/human cytomegalovirus (HCMV)-gB recombinant glycoprotein interaction. This finding opens the way to the simple development of new models of water-soluble glycocluster-based thia-calixarenes with wide-ranging antimicrobial activities.

A sophisticated photoactive molecular device has been prepared by combining recent concepts for the preparation of multifunctional nanomolecules (click chemistry on multifunctional scaffolds) with supramolecular chemistry (self-assembly to prepare rotaxanes). Specifically, a clickable [2]rotaxane scaffold incorporating a free-base porphyrin stopper has been prepared and functionalized with ten peripheral Zn(II)-porphyrin moieties. Electrochemical investigations of the final compound revealed a peculiar behavior resulting from the intramolecular coordination of the Zn(II) porphyrin moieties to 1,2,3-triazole units. Finally, steady state investigations of the compound combining Zn(II) and free-base porphyrin moieties have shown that this compound is a light-harvesting device capable of channeling the light energy from the peripheral Zn(II)-porphyrin subunits to the core by singlet-singlet energy transfer., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Pillar[5]arene derivatives bearing peripheral porphyrin subunits have been efficiently prepared from a deca-azide pillar[5]arene building block (17) and Zn II -porphyrin derivatives bearing a terminal alkyne function (9 and 16). For the resulting deca-Zn II -porphyrin arrays (18 and 20), variable temperature NMR studies revealed an intramolecular complexation of the peripheral Zn II -porphyrin moieties by 1,2,3-triazole subunits. As a result, the molecules adopt a folded conformation. This was further confirmed by UV/Vis spectroscopy and cyclic voltammetry. In addition, we have also demonstrated that the coordination-driven unfolding of 18 and 20 can be controlled by an external chemical stimulus. Specifically, addition of an imidazole derivative (22) to solution of 18 or 20 breaks the intramolecular coordination at the origin of the folding. The resulting molecular motions triggered by the addition of the imidazole ligand mimic the blooming of a flower., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

New liquid-crystalline pillar[5]arene derivatives have been prepared by grafting first-generation Percec-type poly(benzylether) dendrons onto the macrocyclic scaffold. The molecules adopt a disc-shaped structure perfectly suited for self-organization into a columnar liquid-crystalline phase. In this way, the pillar[5]arene cores are piled up, thus forming a nanotubular wire encased within a shell of peripheral dendrons. The capability of pillar[5]arenes to form inclusion complexes has been also exploited. Specifically, detailed binding studies have been carried out in solution with 1,6-dicyanohexane as the guest. Inclusion complexes have also been prepared in the solid state. Supramolecular organization into the Colh mesophase has been deduced from X-ray diffraction data and found to be similar to that observed within the crystal lattice of a model inclusion complex prepared from 1,4-dimethoxypillar[5]arene and 1,6-dicyanohexane., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The title compound, C(47)H(60)O(6).3CHCl(3), is the first example of a lower-rim mono-ester calixarene derivative to be crystallographically characterized. The cone conformation adopted by the macrocycle is stabilized by three intramolecular hydrogen bonds. Self-inclusion of the methyl ester chain in the cavity of an adjacent molecule gives rise to infinite chains parallel to the c axis. C-H...pi interactions involving the methyl group most imbedded in the cavity contribute to the stabilization of the system.

A series of mixed [2 + 2'] p-tert-butylcalix[4]arene have been synthesised by selective 1,3-dialkylation of phenolic groups using various alkylating agents such as benzyl bromide, methyl iodide, ethyl bromoacetate, and 2-methoxyethyl tosylate. The extraction and complexation properties of the synthesized calixarenes towards alkali and alkaline earth metal cations have been investigated in acetonitrile by means of UV spectrophotometry and 1H NMR spectroscopy. The results show the formation of ML and/or ML2 species depending on the ligand and the cation. The enthalpies and entropies of complexation of alkali metal cations by a tetraglycol, diglycol-dibenzyl and diglycol-diester derivatives have been obtained from calorimetric measurements. The results revealed that the formation of ML species is controlled by enthalpy while the formation of ML2 from ML is entropy driven., (Copyright 2004 The Royal Society of Chemistry)