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Synthesis of mono and bis-substituted asymmetrical compounds, (1-(pyridin-2-yl)ethylidene)carbohydrazide and 1-(2-hydroxy-3- methoxybenzylidene)-5-(1-(pyridin-2- yl)ethylidene)carbohydrazide: Structural characterization andantioxidant activity study

A new dissymmetrical ligand 1-(2-hydroxy-3-methoxybenzylidene)-5-(1-(pyridin-2- yl)ethylidene)carbohydrazide (H3L 2 ) was synthetized from the precursor (1-(pyridin-2- yl)ethylidene)carbohydrazide (H5L 1 ) which is obtained bya monocondensation reaction of carbohydrazide with 2-acetylpyridine.The two compounds were characterized by Physico-chemical analyses, elementalanalysis, FTIR,1H and 13C NMR spectroscopy techniques. The structures of the two compoundswere determined by single-crystal X-ray diffraction study. The precursor H5L 1 (C8H11N5O) crystallizes in the monoclinic space group P21/c with the following unit cellparameters: a = 8.9329 (5) Å, b = 9.8728 (4) Å, c = 10.5538 (7) Å, ? = 94.155 (7)°, V = 928.32 (9) Å3, Z = 4, R1 = 0.0445, wR2 = 0.112. The ligand H3L 2 (C17H21N5O4) crystallizes in the triclinic space group P-1 with the following unit cell parameters: a = 7.2851 (3) Å, b = 10.4542 (6) Å, c = 12.0306 (5) Å, a = 87.973 (4)°, ? = 79.372 (4)°, ? = 69.850 (5)°, V = 845.02 (7) Å3, Z = 2, R1 = 0.044, wR2 = 0.1274. The crystal packing of compound H5L 1 is stabilized by intermolecular N–H···O(carbohydrazide) hydrogen bonds which form layers parallel to b axis. The crystal packing of compound H3L 2 is stabilized by intramolecular [(O(Phenol)–H···N(carbohydrazide) and EtO–H···N(pyridine)] and intermolecular hydrogen bonds which form layers parallel to b axis.Each of the two arms of the carbohydrazide is almost coplanar with his corresponding aromatic ring : C6=N2–N3–C8=O and pyridine [4.76°]; C9=N5–N4–C8=O and phenyl [5.29°]. The dihedral angle between the mean planes of the phenyl and the pyridine rings is 5.43°.The antioxidant activities of the two compounds were investigated


Auteur(s) : Thierno Moussa Secka , Fatou Dieng Fayea , Aïssatou Alioune Gayea , IbrahimaElhadjiThiama , Ousmane Dioufa , James Ortonb , Simon Colesb , and Mohamed
Pages : 31-39
Année de publication : 2020
Revue : IOSR Journal of Applied Chemistry (IOSR-JAC)
N° de volume : 13(11)
Type : Article
Mise en ligne par : GAYE Mohamed Lamine