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Updated: Aug 4, 2025
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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Novel Antioxidants Based on Selected 3d Metal Coordination Compounds with 2-Hydroxybenzaldehyde
Vasilii Graur1, Anastasia Mardari, Pavlina Bourosh
1Moldova State University. vgraur@gmail.com.
Abstract:
2-Hydroxybenzaldehyde 4,S-diallylisothiosemicarbazone (HL) was synthesized and characterized by 1H, 13C NMR and FTIR spectroscopies. It exists in solution in two isomeric forms: cis (~25%) and trans (~75%). Six stable complexes were obtained by interaction of HL with copper(II), nickel(II), cobalt(III) and iron(III) salts: [Cu(L)Cl] (1), [Cu(L)NO3] (2), [Cu(3,4-Lut)(L)NO3] (3), [Ni(L)OAc] (4), [Co(L)2]Cl (5), [Fe(L)2]NO3 (6). The synthesized complexes have been studied by elemental analysis, FTIR, molar electrical conductivity and single crystal X-ray diffraction (6). For all compounds the antioxidant activity against cation radicals ABTS•+ was studied. All complexes and free ligand are more active than trolox that is used in medicine practice. Complex 4 (IC50=7.20µM) is the most active one. The introduction of heterocyclic amine did not improve the antioxidant activity. The introduction of S-allyl group into isothiosemicarbazone affected the activity of the synthesized substances, and in some cases the resulting complexes exhibit greater activity than complexes with isothiosemicarbazones with other S-radicals.
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