The utilization of neutral receptors for the molecular recognition of anions based on chalcogen bonding (ChB) is an undeveloped area of host‐guest chemistry. In this manuscript, the synthesis of two new families of sulfur, selenium, and tellurium‐based ChB binding motifs are reported. The stability of the thiophene, selenophene, and tellurophene binding motifs has enabled the determination of the association constants for ChB halide anion binding in the polar aprotic solvent THF by 1H, 77Se, and 125Te NMR experiments. Two different aromatic cores are used and one or two Ch‐binding motifs are incorporated with the purpose of encapsulating the anion, offering up to two concurrent chalcogen bonds. Theoretical calculations and NMR experiments reveal that, for S and Se receptors, hydrogen‐bonding interactions involving the acidic H atom adjacent to the chalcogen atom are energetically favored over the ChB interaction. However, for the tellurophene binding motif, the σ‐hole interaction is competitive and more favored than the hydrogen bond.

We describe here a comparative study between two tripodal anion receptor based on selenophene as binding motif, the receptors use benzene or perfluorobenzene as spacer. The presence of the electron-withdrawing...

1,4-Naphthoquinone and 3-iodo-1,4-naphthoquinone have been explored as hydrogen- or halogen-binding sites for anions integrated in ester based receptors which selectively recognize sulfate anions.

How did the collaborationo nt his project start?We have recently created an etwork of supramolecular chemistry groups in Spain comprising fifteen Universities and Research Institutes named "Functional Supramolecular Materials" (SUPRAMAT) that has obtained financial support by the Spanish Government. The Supramolecular Chemistry Group headed by Prof. Antonio Caballero at the University of Murcia is one of the members of this net. Moreover,P rof. Antonio Frontera is the co-leader of the Supramolecular Group at the University of the Balearic Islands that also belongs to the net. SUPRAMATi si ntended to promote collaborations between the different groups. This collaboration started spontaneously (thermodynamically favored) since Caballero's group was working on the molecular recognition of anions based on chalcogen bonds and Frontera's group was working on the theoretical study of the physical nature of chalcogen bonding interactions when the network was created. In fact, the combination of theory and experiment in this work to has been extremely useful to rationalize the experimental findings, specially the NMR titrations and the movement of the different signals upon addition of the anion.How did each team member contribute to the work?Caballero'sg roup in Murcia carried out the synthesis and spectroscopic characterization of the three families of receptors, including the tellurophene-based ones. It should be emphasized that receptors containing tellurium are scarcely found in the literature. Moreover,t his group has carried out the titrations and fitting of the experimental data to determine the association constants. Frontera's group has performed the theoretical study by using the molecular electrostatic potential surfaces. These surface plots have resulted to be an important contribution to this work because they shed light into the binding site where the anion is placed upon complexation that is actually different from the binding site that both groups envisaged when the receptors were designed. What was the inspiration for this cover design?The cover represents one of the tellurophene based receptors described in this work, which is capable of binding chloride anion in solution through the cooperative action of two different interactions, hydrogen and chalcogen bonding interactions. The anion receptor is represented by using the molecular electrostatic potential surface with different perspectives in order to show the most favorable areas for the anion recognition and especially the sigma hole present in the chalcogen atom. Receptor-anion complexes, free receptors, and free anions in equilibrium are all shown to represent the different species that coexist in the solution. Who designedt he cover?The cover was designed by Dr.A.A.Lozano-PØrez.

The synthesis and halide binding studies of three new families of sulfur, selenium, and tellurium‐based anion receptors based on chalcogen bonding interactions are reported. More information can be found in the Full Paper by A. Frontera, A. Caballero, et al. on page 4706.