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

Photohomolysis and Photoheterolysis in Aryl Sulfonates and Aryl Phosphates

The photochemical behaviour of selected aryl sulfonates and phosphates (ArOX) in polar and nonpolar media has been investigated by laser flash photolysis (LFP) experiments. Two main pathways have been identified, namely the photohomolysis of the ArO−X bond or the photoheterolysis of the Ar−OX bond depending on the nature of the leaving group (OX) and on the nature of the substituents on the aromatic ring. In nonpolar solvents the esters are quite photostable due to an efficient triplet deactivation. In polar solvents, the homolytic fragmentation of the ArO−S bond from the exited singlets was found in aryl sulfonates bearing moderately electron-donating groups as well as electron-withdrawing groups. In electron-rich aryl phosphates and sulfonates photoheterolysis of the Ar−OP/Ar−OS bond took place as the exclusive pathway.Fil: Bonesi, Sergio Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Protti, Stefano. Universita degli Studi di Pavia; ItaliaFil: Fagnoni, M.. Universita degli Studi di Pavia; Itali

Photochemistry of para substituted benzanilides in solution:Preparative and mechanistic studies

Preparative and mechanistic studies on the photochemical reaction of a series of p-substituted benzanilides in polar and nonpolar solvents have been carried out. The aim of this work is mainly focused to show whether the reaction solvent and the electronic effects of the substituents affect the product distribution, the chemical yields and the rate of formation of the 5-substituted-2-aminobenzophenone derivatives. Application of the Hammett linear free energy relationship (LFER) on the rate of formation of 2-aminobenzophenone derivatives, on the lower energy band of the UV–visible absorption spectra of the benzanilides and 5-substituted-2-aminobenzophenone derivatives allows a satisfactory quantification of the substituent effects. Furthermore, the solvent effect was also analyzed on the photoreaction by means of the Reichardt’s solvent parameter (ET(30). Finally, (TD-) DFT calculations have been carried out to support the trends observed experimentally. Graphical abstract: [Figure not available: see fulltext.]