The ability of perfluorinated terephthalonitrile to act as an anion-pi donor fragment in anion receptors is evaluated. New receptors combining an urea and a perfluorinated terephthalonitrile motif into a single architecture have been designed and synthesized. Their molecular recognition properties towards Cl-, Br- and I-, have been studied in solution by means of H-1 and F-19 NMR as well as photophysical experiments. A complementary electrospray ionization-tandem mass spectrometry study confirmed the ranking of recognition properties between the receptors. A further theoretical evaluation of binding properties confirmed the association constant trend and suggests a main contribution of the urea motif weakly complemented by a eta(2)-type anion-pi interaction.

Anion recognition represents an active area of research in supramolecular chemistry. The last two decades have been marked by spectacular advances in the design of new anion receptors. Moreover, the development of approaches combining experimental and theoretical studies has proved to be particularly relevant, allowing for a better understanding and rationalization of the phenomena involved in anion complexation processes. In this context, the combination of weak interactions within the same receptor and their synergistic effects, called cooperativity, has attracted increasing interest within the scientific community. This Review focuses on the combination of anion-pi and hydrogen bonds and the emerging concept of cooperativity. The most relevant anion-pi donor families are presented. The concept of cooperativity is illustrated using the most recent examples present in current literature.

The Front Cover shows the combination of anion-π interaction and hydrogen bonding, which provides some synergistic effects called “cooperativity”. On this cover picture, this recent concept of supramolecular chemistry is illustrated by two characters that help each other to select and recognize anions of different size and shapes. The cartoon was created by Mrs. Naseem Farzand. More information can be found in the Review by R. Plais et al.

Modulation and fine-tuning of the strength of weak interactions to bind anions are described in a series of synthetic receptors. The general design of the receptors includes both a urea motif and a tetrazine motif. The synthetic sequence towards three receptors is detailed. Impacts of H-bond strength and linker length between urea and tetrazine on chloride complexation are studied. Binding properties of the chloride anion are examined in both the ground and excited states using a panel of analytical methods (NMR spectroscopy, mass spectrometry, UV/Visible spectroscopies, and fluorescence). A ranking of the receptors by complexation strength has been determined, allowing a better understanding of the structure-properties relationship on these compounds.

1,2,4-Triazoles are important heterocyclic motifs that are widely found in molecular architectures with medicinal and pharmaceutical properties. Considering the importance of these scaffolds, many works have been published over the last few decades. This review provides a focus on the synthetic approaches towards 1,2,4-triazole derivatives from common precursors such as amidines, imidates, amidrazones, aryldiazoniums and hydrazones over the last decade. This review also aims to provide an overview of triazole derivatives biological properties within the last two years.

Molecular designs merging circularly polarized luminescence (CPL) and thermally activated delayed fluorescence (CP-TADF) using the concept of chiral perturbation appeared recently as a cornerstone for the development of efficient CP-organic light emitting diodes (CP-OLED). Such devices could strongly increase the energy efficiency and performances of conventional OLED displays, in which 50% of the emitted light is often lost due to the use of antiglare filters. In this context, herein, ten couples of enantiomers derived from novel chiral emitter designs are reported, exhibiting CPL, TADF, and aggregation induced enhancement emission properties (AIEE). Representing the first structure properties relationship investigation for CP-TADF materials, this thorough experimental and theoretical work highlights crucial findings on the key structural and electronic parameters (isomerism, nature of the carbazole substituents) governing the synergy between CPL and TADF properties. To conclude this study, the first top emission CP-OLED is elaborated as a new approach of generating CP light in comparison with classical bottom-emission CP-OLED architecture. Indeed, the top-emission configuration represents the only relevant device architecture for future microdisplay applications. Thereby, in addition to offer molecular guidelines to combine efficiently TADF and CPL properties, this study opens new avenues toward practical applications for CP-OLEDs.

The intrinsic properties of tetrazine as a π-anion receptor and as an on/off recognition probe merged with H-bond ability of an urea motif into a single architecture constitutes a new generation of well-defined anion receptors. Complexation properties directly benefit from the dual and synergistic contribution of tetrazine and urea. In this study, we report on the synthesis and assessment of binding properties to anions of diverse geometries. Association constants have been predicted by theoretical calculations and evaluated by multiple and complementary experimental techniques including electrospray-mass tandem spectroscopy, NMR, UV-visible, steady state fluorescence spectroscopies and time resolved fluorescence. These results provide the basis for a better understanding of both the complexation and the anion-dependent quenching mechanism.

The methyl ester of 8-oxo-8H-indeno[2',1':7,8]naphtho[1,2-b]thiophene-2-carboxylic acid (1) and its corresponding PEGylated ester were synthesised and fully characterised. X-ray diffraction studies on (1) confirmed the helical structure of the receptor and that it is self-assembled into layers by π-π interactions. An in-depth study by DFT calculations and MS experiments (ESI-MS, MS/MS, IMRPD and ESI-IMS-MS) was carried out between (1) and the physiological cation K+. The formation of supramolecular complexes between (1) and K+ with different stoichiometries was demonstrated and the cation K+ preferentially interacts with the oxygen atoms of the carbonyl bond of the ketone and ester groups and the sulphur atom of the heterocycle. The ability of the two synthesized aromatic architectures to transport ions across a model lipid membrane has been studied by electrophysiology experiments. The formation of pores was observed, even at nanomolar concentrations. Since the PEGylated molecule showed more regular pore definitions than the hydrophobic molecule, the introduction of a polar hydrophilic chain made it possible to control the orientation of the aromatic architectures within the membrane.

This account outlines our recent investigations towards the synthesis, complexation and properties of pyridylmethylamines (pma) ligands. A careful study combining solid state data, advanced NMR techniques and DFT calculations allowed to study the topology of Pd(II) and Zn(II) complexes and to decipher their privileged structural arrangements. Our approach also permitted to understand the behaviour of catalytic systems in both metal- and organo-catalysis. The efficiency of pma-catalytic systems towards Suzuki couplings, C-H alkylation, C-H arylation, Michael addition and Henry reaction is illustrated through selected examples.