A New Highly Selective Chromogenic and Fluorogenic Chemosensor for Copper (II)

[EN] A new fluorogenic and chromogenic probe (L) for the selective, sensitive and naked-eye detection of Cu2+ is reported. Complexation constant, complex stoichiometry and quantum chemical (DFT) calculation for Cu2+ complex has been determined. Also, detection limits and the selectivity in front of other divalent and trivalent cations have been evaluated.This research was supported by the Agencia Nacional de Ciencia y Tecnologia (ANCyT) of Argentina-PICT 2014 No. 1587 and by the Universidad Nacional del Litoral, Santa Fe, Argentina.Quindt, MI.; Gutiérrez, LG.; Kneeteman, MN.; Mancini, P.; Parra Alvarez, M.; Gil Grau, S.; Costero, AM. (2018). A New Highly Selective Chromogenic and Fluorogenic Chemosensor for Copper (II). Letters in Organic Chemistry. 15(8):659-664. https://doi.org/10.2174/1570178615666180102155804S65966415

Study of a New Hydrazone System with Ion Complexation Capacity Suitable for Selective Detection

The design and synthesis of chemosensors that allows the selectively detection of heavy metal cations by complexation, is an area of growing interest. The hydrazone functional group has been widely used in supramolecular chemistry due to its complexing capacity, its conjugated electrons, and its simple methods of synthesis. In this way, a nitrogen system derived from the condensation of vanillin (aromatic aldehyde) and 2-hydrazinobenzothiazole to give the corresponding hydrazone for the detection of Cu2+ was developed. Spectroscopic determinations demonstrate whether the complexing took place. The hidrazone showed a response in UV–vis spectroscopy and a color shift is observed with the naked eye. In addition, theoretical analysis based on the Density Functional Theory (DFT) was realized to understand the chemical changes that the ligand suffers in the complexation process with the Cu2+ ion through the study of the structural, electronics, and optical properties

Electrochemical Reduction of Oxygen Using a Metal–Organic Complex of Cu²⁺

A biphenyl-based copper complex was evaluated as electrocatalyst for the oxygen reduction reaction (orr), for a possible application as cathode material in fuel cells. To carry out this evaluation, the complex was supported on Vulcan carbon and deposited as a film on a glassy carbon rotating disk electrode by drop-casting a 1-μL drop of a suspension of carbon in a solution of the complex in dimethyl sulfoxide containing Nafion as ionic conductive binder, and drying under vacuum. The cyclic voltammogram in 0.1 M NaOH solution showed voltammetric peaks between 0.8 and 1.0 V vs. reference hydrogen electrode, which suggest the existence of electron transfer processes from/toward the ligand. The orr was tested in oxygen-saturated (1 atm) solution by linear sweep voltammetry, which showed significant orr current at relatively low overpotential (around −0.4 V), demonstrating the ability of the complex to electrocatalyze the orrefficiently