Assembly of organosilver(I) frameworks with terminal ethynide and ethenyl groups on separate pendent arms attached to an aromatic ring

Triazole-Coupled Benzimidazole-Based Fluorescent Sensor for Silver, Bromide, and Chloride Ions in Aqueous Media

A triazole-coupled benzimidazole-based fluorescent probe S1 with nitrogen and oxygen binding sites was synthesized and its properties as a probe for cations were investigated. Probe S1 was found to be highly selective toward Ag⁺ ions in aqueous media. The fluorescence intensity of S1 was quenched as a function of the concentration of Ag⁺ ions in the presence of potential interfering cations with a detection limit of 2.70 μM. The resulting S1-Ag⁺ complex was subsequently studied for its anion recognition abilities and found to recognize Br^- and Cl^- ions, revealing the concentration-dependent fluorescence enhancement with detection limits of 22.2 and 23.0 μM, respectively. Revival of the fluorescence profile of probe S1 indicated that Ag⁺ ion was released from the S1-Ag⁺ complex. Probe S1 is a sensor that can be single-handedly utilized for the qualitative and quantitative determination of Ag⁺, Br^-, and Cl^- ions in aqueous media.

Synthesis, Resolution, and Absolute Configuration of Chiral Tris(2-pyridylmethyl)amine-Based Hemicryptophane Molecular Cages

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.