Anion binding ability and cytotoxicity of a selective colorimetric chemosensor for H2S based on Zn(Ⅱ) complex

Fluorescent half-salen phenoxy-imine zinc complexes to reveal exogenous and endogenous H2S

In this contribution, the synthesis and the reactivity with HS- of a family of half-salen Zn complexes are reported. We provide evidence that HS- binds the zinc center of all the complexes under investigation. DFT and CCSD(T) calculations were performed to model the reactivity of these complexes with HS-. We successfully applied a homoleptic zinc complex bearing a Schiff-based ligand with pyridine pendant arms as a probe for the monitoring of exogenous and endogenous H2S levels in live cells.

Salen-type aluminum and zinc complexes as two-faced Janus compounds: contribution to molecular sensing and polymerization catalysis

The aim of the present review is to highlight the most recent achievements in different fields of application of salen-based zinc and aluminum complexes. More specifically this article focuses on the use of aluminum and zinc salen-type complexes as optical probes for biologically relevant molecules, as catalysts for the ring opening polymerization (ROP) of cyclic esters and co-polymerization of epoxides and anhydrides (ROCOP) and in the chemical fixation of carbon dioxide (CO2). The intention is to provide an overview of the most recent results from our group within the framework of the state-of-art-results in the literature.

Nanomolar Detection of H2S in an Aqueous Medium: Application in Endogenous and Exogenous Imaging of HeLa Cells and Zebrafish

The homeostasis of short-lived reactive species such as hydrogen sulfide/hypochlorous acid (H2S/HOCl) in biological systems is essential for maintaining intercellular balance. An unchecked increase in biological H2S concentrations impedes homeostasis. In this report, we present a molecular probe pyrene-based sulfonyl hydrazone derived from pyrene for the selective detection of H2S endogenously as well as exogenously through a "turn-off" response in water. The structure of the receptor is confirmed by Fourier-transform infrared spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry, and single-crystal X-ray diffraction studies. The receptor shows excellent green emission in both the aqueous phase and solid state. Quenching of green emission of the receptor is observed only when H2S is present in water with a detection limit of 18 nM. Other competing anions and cations do not have any influence on the receptor's optical properties. The efficiency of H2S detection is not negatively impacted by other reactive sulfur species too. The sensing mechanism of H2S follows a chemodosimetric reductive elimination of sulfur dioxide, which is supported by product isolation. The receptor is found to be biocompatible, as evident by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and its utility is extended to endogenous and exogenous fluorescence imaging of HeLa cells and zebrafish.

Simultaneous measurement of hydrogen carbonate and acetate anions using biologically active receptor based on azo derivatives of naphthalene

A novel receptor based on azo-derivatives of 1-naphthylamine (2-((E)-((4-chloro-3-(trifluoromethyl)phenyl)imino)methyl)-4-((E)-naphthalene-1-yldiazenyl)phenol(2) abbreviated CTNP was successfully designed and synthesized. Its sensing properties were studied deeply. Systematic studies of CTNP with HCO₃^- and AcO^- anions in DMSO disclosed that there is hydrogen-bonding between CTNP and incoming anions. Significant changes in the visible region of the spectrum, as well as a drastic color change of CTNP from pale yellow to red, observed due to interaction as mentioned earlier. The stoichiometry of [CTNP: HCO₃^- or AcO^-] complexes and association constants determined through Job's method and Benesi-Hildebrand (B-H) plot, respectively. Taking into account the analysis results, CTNP performs the selective recognition of sub-millimolar concentrations of HCO₃^- and AcO^- efficiently. The antifungal activity of the receptor was tested against Aspergillus brasiliensis and Aspergillus niger. CTNP exhibited excellent antifungal activity against both strains. CTNP also represented antibacterial activity against Gram-positive bacteria: Staphylococcus epidermidis. It was cleared that designed receptor can be applied under physiological conditions for a long duration.