Through-the-annulus-catenated calixarenes have been obtained, for the first time, by exploiting the "superweak anion" approach that allows the threading of the calix cavity with functionalized dialkylammonium axles. In addition, the first example of a stereoprogrammed synthesis of a catenane orientational isomer (an oriented calix[2]catenane) has been obtained, after macrocyclization, by using a directional alkylbenzylammonium axle.

A "turn on" fluorescence-based probe for sensing H 2 S in water via a coordinative-based approach has been successfully devised. The probe can selectively detect H 2 S in aqueous solutions over other anions, biothiols, and common

The reaction of alkylcobaloxime [Co(dmgH)2(CH2CH3)(py)] (1) (dmgH = the anion of dimethyl-glyoxime) with KSH in water solution resulted in the selective displacement of the pyridine axial ligand affording the derivative K[Co(dmgH)2(CH2CH3)(SH)] (2). An 1H-1H EXSY experiment revealed that the substitution is reversible and occurs in a slow exchange regime. Attempts to grow crystals of the HS- adduct led to isolation of a rare example of the unexpected trisulfido-bridged dinuclear complex K2[Co2(dmgH)2(CH2CH3)2(μ-S3)]. It was shown that the glyoximato ligands provided the metal centre with a coordination environment quite robust to prevent decomposition and constitute a suitable platform for developing the chemistry of organometallic complexes bearing hydrogensulfido or oligosulfido ligands

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A pentadentate cage‐like cyclam‐based fluorescent ligand has been designed, synthesized, and characterized by 1D and 2D NMR spectroscopic analysis. To further characterize the title ligand, ESI‐MS, UV/Vis spectroscopy, and fluorescence experiments have been also performed. Its suitability as a chemosensor for the detection of Cu2+ ions has been successfully explored with a variety of spectroscopic techniques (i.e., ESI‐MS, UV/Vis, and fluorescence). A Job's plot experiment, together with ESI‐MS experiments, indicate a 1:1 stoichiometry for the binding of Cu2+ to the cyclam‐based ligand. Fluorescence experiments corroborate this hypothesis. The resulting system is selective in the recognition of copper and is stable for a week, as assessed by fluorescence spectroscopy. The CuII complex has been isolated and tested as a fluorescent probe for the detection of H2S. NMR spectroscopy and ESI‐MS investigations have provided evidence that H2S recognition occurs through a copper‐displacement mechanism, as reported in the literature for different copper complexes. The system functions with a selective response to HS–, harnessing a concentration‐dependent “turn‐on” of the initial fluorescence intensity.

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