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The present invention relates to calix[4]arenes of the formula (1a), in which: Y1, Y2, Y3 and Y4 are selected from hydrogen, halogen, NO2, N3, CN, CHO, COOR', CONR"2, NR2, triazole moiety and C1-C3-alkyl group, said C1-C3-alkyl group being optionally substituted, Z is a heterocyclic moiety which is selected from the group consisting of imidazole, benzimidazole, benzothiazole, benzoxazole, purine, tetrazine, oxazole, pyrazole and thiazole, said heterocyclic moiety being optionally substituted, R1 and R2 are selected from hydrogen and C1-C8-alkyl, said C1-C8-alkyl group being optionally substituted, n being an integer comprised between 1 and 4 (preferably equal to 1), They exhibit high cytotoxicity against cancer cells., https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2024156819, info:eu-repo/semantics/published

Few synthetic methodologies that yield tris-functionalized C3v-symmetrical calix[6]arenes have been reported. In this work, three allyl protecting groups are selectively placed in 1,3,5 alternate positions of three pristine calix[6]arenes, each differing by their substituent on the large rim, resulting in three new C3v-symmetrical molecular platforms. Removal of the protecting allylic groups gives access to sophisticated calix[6]arenes that can be further modified. The potential of these new C3v-symmetrical molecular platforms is notably exemplified through the development of a new family of calix[6]arene-based N ligands., SCOPUS: ar.j, info:eu-repo/semantics/published

The synthesis of a series of mononuclear, dicationic CoII funnel complexes is reported herein. Three ligands Calix‐TMPAX present a calix[6]arene cone closed at its small rim by a tris(2‐pyridylmethyl)amine (TMPA) unit and differ by the nature of three cavity walls, anisole, phenol or quinone. The X‐ray diffraction structure of [CoII(MeCN)Calix‐TMPAOMe](ClO4)2 displays a trigonal bipyramidal geometry, with Co bound to all 4 nitrogen atoms of the TMPA cap, and to one MeCN guest molecule buried inside the calixarene cavity. All complexes were fully characterized in solution as high spin 5‐coordinate species using various techniques, including 1H NMR spectroscopy. For comparison purpose, an analogous CoII complex based on the TMPACH2OH ligand, devoid of a calixarene core, was synthetized. Its X‐ray structure shows a dicationic 7‐coordinate cobalt(II) center in the N4O3 environment provided by the ligand, leaving no space for exogenous ligand binding. This contrasts with the 5‐coordinate complexes obtained with the calix‐ligands that allow guest‐ligand binding and exchange. A brief overview of the coordination properties of the calix‐complexes, compared to those obtained with TMPA ligands, devoid of a cavity, highlights major differences in terms of complexation kinetics, geometry, coordination to the labile site, anion affinity, nuclearity, and stability., SCOPUS: ar.j, info:eu-repo/semantics/published

In the quest for more effective colorimetric reporters compared with traditional gold nanoparticles (AuNPs), a family of Au@Ag core-shell nanoparticles was designed and synthesized using a seed growth-mediated approach starting from commercial 37 nm AuNPs. This method enabled precise control over the thickness of the silver shell by employing hydroquinone for the reduction of silver and citrate for stabilization of the resulting core-shell particles. Core-shell NPs with an Ag shell of 7 nm (Au@Ag5NPs) and 18 nm (Au@Ag10NPs) were synthesized, resulting in orange and milky yellow suspension, respectively. Additionally, the impact of an external gold layer on Au@Ag10NPs (Au@Ag10@AuNPs), which significantly altered their optical properties from milky yellow to gray, was investigated. The core-shell Au@AgNPs exhibited substantially higher molar extinction coefficients than their parent AuNPs: from 3.5-fold for Au@Ag5NPs and 9-fold for Au@Ag10NPs and Au@Ag10@AuNPs. Subsequently, all core-shell NPs were functionalized with a calix[4]arene layer, imparting superior stability against external stresses, such as dispersion in PBS, when compared to NPs functionalized with traditional ligands. This calixarene coating enabled the covalent bioconjugation of antibodies on all NP types without inducing noticeable aggregation. Their performance as colorimetric reporters was evaluated in a lateral flow assay for troponin I detection, demonstrating positive signals down to 1 ng/mL, surpassing the detection limit of the parent gold NPs (2.5 ng/mL). Notably, the gray color of the core-shell Au@Ag10@AuNPs provided strong contrast against the white NC membrane, facilitating T-line visualization even at low signal intensity. Despite the lack of optimization of our LFA, it competes with the limit of quantification of commercial LFAs for troponin I detection, offering the potential for the development of a highly sensitive assay. The diverse core-shell NPs employed in this study form a librar, SCOPUS: ar.j, info:eu-repo/semantics/published

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This study introduces peptide aptamers as a promising alternative to conventional antibodies for use as recognition units in lateral flow assays (LFAs). Two distinct strategies for immobilizing peptides onto nitrocellulose (NC) membranes were investigated: the first involved covalent coupling to bovine serum albumin (BSA) using EDC/sulfo-NHS chemistry, while the second utilized the well-known biotin/streptavidin complexation method. The former strategy only requires the addition of a lysine in the peptide sequence, while the latter exploits a commercially widely available chemical modification of these biomolecules. Both methods proved successful in immobilizing the capture probes onto the surface. Furthermore, we employed silver nanoplates functionalized with calixarenes as colorimetric reporters, that we have shown recently to exhibit excellent characteristics for LFAs, including high absorption coefficient, excellent stability, and strong contrast with the NC membrane. The peptide-based assay detected Mdm2, a well-established cancer biomarker, in low nanomolar range even in complex matrixes such as cell lysates. Notably, the utilization of peptide aptamers demonstrated superior performance and extended shelf life compared to polyclonal antibodies, underlining their potential as recognition units in LFAs. In addition to their ease of handling, peptide aptamers utilization also offers the prospect of substantial cost reductions compared to conventional antibody-based LFAs. This comprehensive approach enhances the utility of LFAs for the sensitive and costeffective detection of target proteins using peptide aptamers as recognition units both on the colorimetric reporter and the membrane, opening doors to broader applications in biomarker analysis and diagnostic assays., info:eu-repo/semantics/published

Lateral flow assays (LFAs), such as pregnancy tests or antigen tests, are probably the most widespread point-of-care testing. They combine all their advantages: rapid, low cost, ease of use and straightforward signal. However, LFAs, in biomedical diagnostics, are sometimes considered as not sufficiently reliable due to their poor sensitivity. Indeed, the analyte in extremely low amounts is not detected, increasing the false negative rate. Many strategies were recently developed to enhance the sensitivity of LFAs. In this thesis, investigations were focused on the colorimetric reporters involved in the assay. Indeed, the red-colored signal observed in most of the LFAs is due to the binding of gold nanoparticles (AuNPs), used as colorimetric reporters, at the test line. AuNPs belong to the plasmonic nanomaterials class, which are able to strongly absorb light. However, silver nanoparticles are known to have higher extinction coefficient compared to their gold counterpart, but suffer from a low stability against external stress, limiting their applications. Recently, calix[4]arene-based coating emerged as promising strategy to drastically enhance stability of plasmonic nanoparticles. First, the calix[4]arene-coated AgNPs, with a 20 nm average diameter, were synthesized and used for the detection of Anti-SARS-CoV-2 IgG in clinical samples. Calix[4]arene coating conferred remarkable stability to the resulting AgNPs, as no degradation was observed over several months. In comparison with lateral-flow immunoassays (LFIAs) based on classical gold nanoparticles, the limit of detection for Anti-SARS-CoV-2 IgG was reduced by 1 order of magnitude and similar signals were observed with 10 times fewer particles with our AgNPs-based assay. These results represent one of the first examples of the use of AgNP-based LFA in the case of real clinical samples.Secondly, silver nanoplates (AgNPls) synthesis was developed. In contrast to AgNPs, the absorption spectrum of this anisotropic na, Doctorat en Sciences de l'ingénieur et technologie, info:eu-repo/semantics/nonPublished

Aryl diazonium salts are ubiquitous building blocks in chemistry, as they are useful radical precursors in organic synthesis as well as for the functionalization of solid materials. They can be reduced electrochemically or through a photo-induced electron transfer re- action. Here, we provide a detailed picture of the ground- and excited-state reactivity of a series of nine rare and earth-abundant photosensitizers with 13 aryl diazonium salts, which also included three macrocyclic calix[4]arene tetradiazonium salts. Nanosecond transient absorption spectroscopy confirmed the occurrence of excited-state electron transfer and was used to quantify cage- escape yields (i.e., the efficiency with which the formed radicals separate and escape the solvent cage). Cage-escape yields were large; they increased when the driving force for photo-induced elec- tron transfer increased and also tracked with the C–N2+ bond cleav- age propensity, among others. A photo-induced borylation reaction was then investigated with all the photosensitizers and proceeded with yields between 9% and 74%.

A conceptual challenge toward more versatile direct methanol fuel cell (DMFC) is the design of a single material electrocatalyst with high activity and durability for both oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). This requires to conciliate methanol tolerance not to hinder ORR at the cathode with a good MOR activity at the anode. This is especially incompatible with Pt materials. We tackled this challenge by deriving a supramolecular concept where surface-grafted molecular ligands regulate the Pt-catalyst reactivity. ORR and MOR activities of newly reported Pt-calix[4]arenes nanocatalysts (PtCF3NPs/C) are compared to commercial benchmark PtNPs/C. PtCF3NPs/C exhibit a remarkable methanol tolerance without losing the MOR reactivity along with outstanding durability and chemical stability. Beyond designing single-catalyst material, operable in DMFC cathodic and anodic compartments, the results highlight a promising strategy for tuning interfacial properties.

Gold nanorods (AuNRs) have emerged as highly promising materials for advancing biomedical in vivo applications. They exhibit two distinct Localized Surface Plasmon Resonance (LSPR) bands, namely transverse and longitudinal. The maximum absorption wavelength of the latter can be precisely tuned by adjusting the aspect ratio of the rods. For high aspect ratios, the absorption wavelength falls within the near-infrared (NIR) region, where minimal absorption of light by endogenous molecules enables excellent penetration into tissues. Photothermal therapy (PTT) is a promising noninvasive cancer treatment strategy exploiting the conversion of light to heat by photothermal agents for thermal ablation of cancer cells. PTT has attracted much attention due to its simple operation, short treatment duration, and minimal intrusion. AuNRs possess several qualities that make them excellent photothermal agents: high biocompatibility, long circulation times, ease in functionalization, and intense optial extinction coefficients in the NIR region. However, one limitation is their anisotropic structure that is susceptible to deformation upon laser irradiation leading to a rapid decrease of their NIR extinction and photothermal efficiency. To address this challenge, we have employed an effective approach to stabilize the rod shape, involving the use of calix[4]arene-tetradiazonium salts, which can be irreversibly and strongly grafted onto surfaces through the reduction of their diazonium groups. We have adapted this calixarene-based coating technology to fabricate ultrastable AuNRs which exhibit superior stability compared to conventional AuNRs, notably under laser irradiation., info:eu-repo/semantics/nonPublished

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Our ability to synthetize organic molecules efficiently often revolves around selective reactions. The most commonly studied selectivities are the chemo-, stereo-, and regioselectivities (Figure 1). These selectivities are, however, not sufficient to describe all selective chemical transformations. For instance, when a substrate can undergo the same reaction repeatedly (Figure 2), a new kind of selectivity is needed to obtain one product preferentially. In this context, we conceptualized the “iteroselectivity” that governs the number of repeating chemical transformations that occur on substrates that can undergo at least twice the same reaction.1 Such an iterative process applies to polyfunctional substrates bearing the same type of functional group (e.g. ethylene glycol, sugars, oligomeric macrocycles), and to reactions where the reactive functional group is regenerated (e.g. polymerizations). The different products after each iteration are named iteromers. To achieve high iteroselectivity, it may be necessary to tune the reactivity of the functional groups in a controllable manner. Supramolecular chemistry is a toolbox offering numerous options to modify the reactivity of functional groups by changing their local environment without direct modification of the functional groups in contrast to classical covalent protecting groups. In this communication, we explore examples of iteroselective reactions based on supramolecular protection, supramolecular activation, and templating effects., info:eu-repo/semantics/nonPublished

Visualizing chemical structures in 3D is an important aspect both in chemical education and research. Some chemists may struggle with 3D visualization from mere 2D images, especially for some intricate structures. ChemARise is a free app available on Android (Play store) and iOS (App store) that displays a set of chemical structures in 3D, either from a free structure selection or in augmented reality (AR) when detecting the corresponding 2D images (Figure 1). It is currently used to help students in organic chemistry and supramolecular chemistry courses, and for scientific communication with structures displayed in journal articles and posters., info:eu-repo/semantics/nonPublished

Our ability to synthetize organic molecules efficiently often revolves around selective reactions. The most commonly studied selectivities are the chemo-, stereo-, and regioselectivities (Figure 1). These selectivities are, however, not sufficient to describe all selective chemical transformations. For instance, when a substrate can undergo the same reaction repeatedly (Figure 2), a new kind of selectivity is needed to obtain one product preferentially. In this context, we conceptualized the “iteroselectivity” that governs the number of repeating chemical transformations that occur on substrates that can undergo at least twice the same reaction.1 Such an iterative process applies to polyfunctional substrates bearing the same type of functional group (e.g. ethylene glycol, sugars, oligomeric macrocycles), and to reactions where the reactive functional group is regenerated (e.g. polymerizations). The different products after each iteration are named iteromers. To achieve high iteroselectivity, it may be necessary to tune the reactivity of the functional groups in a controllable manner. Supramolecular chemistry is a toolbox offering numerous options to modify the reactivity of functional groups by changing their local environment without direct modification of the functional groups in contrast to classical covalent protecting groups. In this communication, we explore examples of iteroselective reactions based on supramolecular protection, supramolecular activation, and templating effects., info:eu-repo/semantics/nonPublished

The kinetics of ligand exchange at a Zn II center confined in a biomimetic environment is studied., info:eu-repo/semantics/published

A conceptual challenge toward more versatile direct methanol fuel cells (DMFCs) is the design of a single material electrocatalyst with high activity and durability for both oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). This requires to conciliate methanol tolerance not to hinder ORR at the cathode with a good MOR activity at the anode. This is especially incompatible with Pt materials. We tackled this challenge by deriving a supramolecular concept where surface‐grafted molecular ligands regulate the Pt‐catalyst reactivity. ORR and MOR activities of newly reported Pt‐calix[4]arenes nanocatalysts (Pt NPs/C) are compared to commercial benchmark PtNPs/C. Pt NPs/C exhibit a remarkable methanol tolerance without losing the MOR reactivity along with outstanding durability and chemical stability. Beyond designing single‐catalyst material, operable in DMFC cathodic and anodic compartments, the results highlight a promising strategy for tuning interfacial properties., SCOPUS: ar.j, info:eu-repo/semantics/published

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Due to their significant role in industry and biological systems, the interest in selectively recognizing and detecting small dicarboxylates has grown in recent years. In this study, we report on the binding properties of a family of tubular-shaped heterotritopic receptors based on bis-calix[6]arenes, which contain three (thio)urea bridges (C3U and C3TU) or six urea bridges (C6U), toward dicarboxylates. While poor binding properties were observed by NMR for the newly synthesized C6U, receptors C3U and C3TU exhibited a unique ability to cooperatively complex a dicarboxylate anion sandwiched between two ammonium ions. The three ions are complexed in contact and aligned within the tubular shape of the receptor, forming cascade complexes that are stable even in a competitive environment. The different binding properties between the receptors were rationalized in terms of size, flexibility, H-bond donor ability, and intramolecular H-bonding within the anion binding pocket between the calixarene cavities. With C3U, a rare selectivity for oxalate over other small dicarboxylates and various bicharged anions was observed. Molecular modeling of the cascade complex indicated that the oxalate anion is stabilized by an array of hydrogen bonds with the urea bridges of the receptor and both propylammonium cations nested within the calixarene cavities., info:eu-repo/semantics/published

Our ability to synthetize organic molecules efficiently often revolves around selective reactions. The most commonly studied selectivities are the chemo-, stereo-, and regioselectivities. These selectivities are, however, not sufficient to describe all selective chemical transformations. For instance, when a substrate can undergo the same reaction repeatedly (Figure 1), a new kind of selectivity is needed to obtain one product preferentially. In this context, we conceptualized the “iteroselectivity” that governs the number of repeating chemical transformations that occur on substrates that can undergo at least twice the same reaction.1 Such an iterative process applies to polyfunctional substrates bearing the same type of functional group (e.g. ethylene glycol, sugars, oligomeric macrocycles), and to reactions where the reactive functional group is regenerated (e.g. polymerizations). The different products after each iteration are named iteromers. To achieve high iteroselectivity, it may be necessary to tune the reactivity of the functional groups in a controllable manner. Supramolecular chemistry is a toolbox offering numerous options to modify the reactivity of functional groups by changing their local environment without direct modification of the functional groups in contrast to classical covalent protecting groups. In this communication, we explore examples from the literature of iteroselective reactions based on supramolecular protection, supramolecular activation, and templating effects., info:eu-repo/semantics/nonPublished

Noble metal anisotropic nanostructures, such as silver nanoplates (AgNPls), are interesting because they possess enhanced plasmonic properties compared to their spherical counterparts: increased extinction coefficient and tunable maximum of absorption wavelength. However, their use for biosensing application is limited as these structures are intrinsically unstable and, to maintain the anisotropic structure, a coating protecting the metallic surface is required. In this work, we report on the capacity of a thin but robust coating based on calixarene-diazonium salts to maintain the structure anisotropy of silver nanoplates in conditions in which traditionally used coatings fail. We synthesized AgNPls of various sizes and coated them with two different calixarenes, differing by the functional groups attached to their small rim. After characterization of the efficiency of the ligand exchange process between the initial citrate anions and the calixarenes, the chemical and colloidal stabilities of the resulting calixarene-coated AgNPls were compared to citrate-capped AgNPls. A radical improvement of the lifetime of the material from 1 day for AgNPls coated with citrate to more than 900 days for calixarene-coated AgNPls, as well as the stability in acidic conditions, phosphate saline buffer (PBS) or biofluid, were observed. Benefiting from this exceptional robustness, calixarene-coated AgNPls were exploited to design dipstick assays. Rabbit immunoglobulin G (IgG) detection was developed first as proof-of-concept. The optimal system was then used for the detection of Anti-SARS-CoV-2 IgG. In both cases, a picomolar limit of detection (LOD) was achieved as well as the detection in 100% of pooled human plasma. This sensitivity competes with that of ELISA and is better than the one previously obtained with gold or even silver nanospheres for the same target and in similar conditions. Finally, the wide range of colors provided by the AgNPls allowed the design of a multicolor mu, info:eu-repo/semantics/published

Synthetic molecular receptors can find applications in many areas among which the selective extraction, transport or detection of different species. In this thesis we focused our attention on the study of macrocyclic hexahomotrioxacalix[3]arenes. These receptors possess an 18-membered macrocycle resembling a crown ether (the 18 crown 6 ether) and when they are in their cone conformation, a cavity formed by three aromatic units.In the first part of this thesis, the binding properties of hexahomotrioxacalix[3]arene receptors towards ammonium ions were studied by 1H NMR spectroscopy and in silico methods. Our results showed that these receptors bind primary ammonium ions, including biomolecules, in their polyaromatic cavity even in a competitive environment (CDCl3/CD3OD (4:1)). A binding mode, similar for all guests, was reported with the ammonium head (NH3+) deeply inserted in the polyaromatic cavity of the receptor, enabling the formation of three H-bonds with the ethereal oxygens of the macrocycle. The high complementarity between primary ammonium ions and the receptors results in an unprecedented specificity for primary ammonium ions over secondary, tertiary and quaternary ones. The selective liquid-liquid extraction of primary ammonium salts from water and the selective recognition of lysine-containing peptides was achieved with these receptors. Our results have been reported in the paper “Specific Binding of Primary Ammonium Ions and Lysine-Containing Peptides in Protic Solvents by Hexahomotrioxacalix[3]arenes” Simon Lambert, Kristin Bartik and Ivan Jabin J. Org. Chem. 2020, 85, 10062-10071.In the second part of this thesis, a fluorescent hexahomotrioxacalix[3]arene was developed for the sensing of primary ammonium ions. A pyrene group was grafted on the large rim of an hexahomotrioxacalix[3]arene and its binding properties were studied by 1H NMR spectroscopy, in silico methods and fluorescence spectroscopy. Binding properties similar to those of the non-function, Doctorat en Sciences de l'ingénieur et technologie, info:eu-repo/semantics/nonPublished

Parmi les systèmes biologiques, on trouve des protéines contenant des centres métalliques dans des architectures bien définies. Celles-ci sont appelées métalloprotéines et font partie des systèmes les plus efficaces pour la détection de petites molécules, le transfert d’électrons ou encore la catalyse. La majorité des métaux impliqués dans ces processus sont des métaux de transition Certaines de ces métalloprotéines sont redox-actives et peuvent associer un cofacteur organique redox directement lié à la chaîne protéique de manière covalente qui joue alors un rôle essentiel dans la catalyse en elle-même ou dans la régénération du catalyseur (ie l’état d’oxydation du centre métallique). On retrouve plusieurs types de cofacteurs organiques redox comme les groupements phénols (résidu tyrosine) ou les groupements quinones. Ces systèmes sont particulièrement adaptés dans la catalyse de petites molécules et le transfert de multiples protons et électrons. Par exemple la cytochrome c oxidase permet la transformation extrêmement efficace de O2 en H2O via le transfert très sélectif de 4 électrons et 4 protons. L’une des transformations de petite molécule qui concentre le plus d’efforts de la recherche scientifique est la catalyse du CO2 en raison de clairs enjeux climatiques associés à son émission excessive par l’homme et sa contribution au réchauffement climatique. L’objectif de cette thèse est d’associer les différents éléments caractéristiques de ces métalloenzymes en un seul système synthétique basé sur les calixarènes. En effet un calixarène chapeauté par un ligand polyazoté permet de reproduire 1) une cavité adaptée à de petites molécules, 2) des cofacteurs organiques situé à distance idéale d’un 3) centre métallique enfoui dans la cavité. La stratégie de cette thèse a donc été de synthétiser les ligands calixaréniques ciblés ainsi que leurs complexes de ZnII d’une part et d’autre part les complexes de CoII correspondant puisque ce dernier est un des métaux les plus pro, Doctorat en Sciences, info:eu-repo/semantics/nonPublished

Our ability to synthetize organic molecules efficiently often revolves around selective reactions. The most commonly studied selectivities are the chemo-, stereo-, and regioselectivities. These selectivities are, however, not sufficient to describe all selective chemical transformations. For instance, when a substrate can undergo the same reaction repeatedly (Figure 1), a new kind of selectivity is needed to obtain one product preferentially. In this context, we conceptualized the “iteroselectivity” that governs the number of repeating chemical transformations that occur on substrates that can undergo at least twice the same reaction.1 Such an iterative process applies to polyfunctional substrates bearing the same type of functional group (e.g. ethylene glycol, sugars, oligomeric macrocycles), and to reactions where the reactive functional group is regenerated (e.g. polymerizations). The different products after each iteration are named iteromers. To achieve high iteroselectivity, it may be necessary to tune the reactivity of the functional groups in a controllable manner. Supramolecular chemistry is a toolbox offering numerous options to modify the reactivity of functional groups by changing their local environment without direct modification of the functional groups in contrast to classical covalent protecting groups. In this poster, we explore examples from the literature of iteroselective reactions based on supramolecular protection, supramolecular activation, and templating effects., info:eu-repo/semantics/nonPublished

The development of synthetic molecules able to transport ions through lipid bilayer membranes is of growing interest in the field of supramolecular chemistry. The balance of anions and cations has an important role in the biology of all living organisms. This thesis will focus on the development of copper(I) transporters, the methodologies developed to study them, and their biological applications. The first part of this thesis is focused on the development of copper(I) transmembrane transporters and the methodology required for their study. These transporters were developed for a potential therapeutic application, with the idea that synthetic copper(I) transporters could replace dysfunctional copper(I) transport proteins, which are responsible for distributing copper(I) within cells. Dysfunction of these proteins is the cause of Wilson and Menkes diseases.Calix4arene functionalised with two imidazole groups can strongly bind copper(I) through a linear coordination motif. This ability and their high lipophilicity made them good candidates to transport copper(I) through bilayer membranes. For that, a new assay was developed using liposomes as model systems for membranes, in which a phenanthroline based copper(I) sensitive dye is encapsulated. The changes in fluorescence as monitored by spectroscopy allowed for the observation of copper(I) transport. Most of these results are reported in the publication: “Transmembrane transport of copper(I) by imidazole-functionalised calix[4]arenes” N. Renier, O. Reinaud, I. Jabin, and H. Valkenier. Chem. Commun. 2020, 56, 8206-8209. The improvement and limitations of the transport assay are also described. In the second part, the development of a deliverable copper(I) transporter is described along with the biological effects of the compound on various biological systems. A new transporter was synthesised and shown to be able to reach liposomes membrane when added from an organic solution or from other liposomes, which was not th, Doctorat en Sciences de l'ingénieur et technologie, info:eu-repo/semantics/nonPublished

A series of surface-functionalized gold nanocatalysts are synthesized. Through diazonium chemistry, calix[4]arene molecules are grafted at the gold surface. Sharing the same anchoring function and a common backbone, the calix[4]arene ligands possess distinct terminal chemical functions where the length, hydrophobic nature, and oxygen affinity are varied. Thanks to the versatility of the calix[4]arene platform, this paper only focuses on the molecular tuning of the solid/liquid interface through the change of the tail groups while electronic effects that are regulated by the anchoring function will be similar for all catalysts. Electrocatalytic tests demonstrate the influence of the tails group on the oxygen reduction reaction performances, including efficiency, selectivity, and durability. Beyond a pure geometric steric effect, it is shown that chemical properties of the ligands can effectively tune the interactions between the metallic catalyst and the electrolyte and reactants., SCOPUS: ar.j, info:eu-repo/semantics/published

In the biomimetic context, many studies have evidenced the importance of the 1st and 2nd coordination sphere of a metal ion for controlling its properties. Here, we propose to evaluate a yet poorly explored aspect, which is the nature of the cavity that surrounds the metal labile site. Three calix[6]arene-based aza-ligands are compared, that differ only by the nature of cavity walls, anisole, phenol or quinone (LOMe, LOH and LQ). Monitoring ligand exchange of their ZnII complexes evidenced important differences in the metal ion relative affinities for nitriles, halides or carboxylates. It also showed a possible sharp kinetic control on both, metal ion binding and ligand exchange. Hence, this study supports the observations reported on biological systems, highlighting that the substitution of an amino-acid residue of the enzyme active site, at remote distance of the metal ion, can have strong impacts on metal ion lability, substrate/product exchange or selectivity., SCOPUS: ar.j, info:eu-repo/semantics/published

A novel ZnII funnel complex that presents three phenol functions within the calix[6]arene macrocycle is described. Host-guest studies, monitored by 1H NMR spectroscopy, evaluate the impact of the replacement of three anisole moieties present in the previously described system by phenols. It is shown that now the dicationic complex is responsive to anions, whereas deprotonation of one phenol unit completely inhibits any hosting response. These properties, combined with those of the corresponding protonated ligand, allow to obtain different molecular switches, one of which yielding guest embedment changes between four different host states, thus giving rise to a rare case of triple molecular switch., info:eu-repo/semantics/published

The kinetics of ligand exchange at a ZnII center confined in a biomimetic environment is studied. The metal ion is bound to a TMPA unit covalently capping the calix[6]arene core. As such, the system is rigidified in a cone conformation open to the solvent at the large rim. At the small rim, the methyl groups of the anisole units lead to steric crowding, thus defining a small pore leading to the metal center. The exchange of an organic guest ligand (MeCN) for another (EtCN) is studied by 1H NMR spectroscopy. It is shown that it is very slow under dry conditions (several hours at mM concentrations), but much faster in the presence of appreciable amounts of water. Kinetic analyses indicate that the exchange process involves the transient formation of an aqua complex that was independently synthesized and well characterized. Computer studies suggest that transient water coordination first occurs through the small rim pore, in exo-position. The water molecule then flips in endo-position, as the MeCN guest decoordinates and exits from the cavity through the large rim. This allows another organic guest ligand to get in, with release of the catalytic water to the solvent. Steered molecular dynamics simulations also show the assistance of the second coordination sphere of the metal ion for the exo/endo flipping process of the water ligand through H-bonding to the oxygenated small rim of the calixarene macrocycle. Importantly, it appeared that only water can play such a catalytic role, due to size selection by the pores defined by the calixarene small rim. From a biological point of view, it further substantiates the importance of water molecules and micro-environment on metal ion lability., SCOPUS: ar.j, info:eu-repo/semantics/published