Élaboration et caractérisation structurale et magnétique de complexes de coordination homonucléaires 3d et hétéronucléaires 3d-4f avec différentes bases de Schiff à propriétés anti-oxydantes et anti-alzheimer.

Abstract

The present work concerns the synthesis and structural, magnetic and biological characterization of two series of coordination complexes based on transition metals for the first and transition metals and lanthanides for the second with different schiff bases ligands. The reaction of 2-thiophenecarboxylic acid (L) with copper ions, has led to three structures including a monomer and two dimers with respective general formulas: [Cu (L)2], [Cu2(μ-Cl)2(HL)2Cl2], [Cu2 (μ-L)4 (L-méthyl ester)] ; HL : N'- (propan-2-ylidène) thiophène-2-carbohydrazide. While the reaction of the three enantiomers (R,R; S,S and R,S) of the Salen Sciff bases 2,2'-[[(1C*,2C*)-1,2-diphenyl-1,2-ethanediyl]-bis[(E)nitrilomethylidyne] bis[6-ethoxy], with lanthanide ions and Zn (ll) / Ni (ll) ions, leds to seven chiral hetero-bimetallic complexes with the formulas: C*,C*-[ZnLDy(m-OAc)(NO3)2], R,R-[ZnLYb(m-OAc)(NO3)2], C*,C*-[NiLDy(NO3)3] ; C*,C*: R-R, S-S, R-S; L: 2,2'-[[(1C*,2C*)-1,2-diphenyl-1,2-ethanediyl]bis[(E) nitrilomethylidyne] bis[6-ethoxy] The structural and physico-chemical properties of the compounds have been studied using several techniques : such as single crystal X-ray diffraction, infrared spectroscopy, elementary analysis, ATG and magnetic measurements on squid. for the biological properties (antioxidant et anti-alzheimer), two compounds have a noticeable effect on the inhibition of free radicals ABTS or reduction of copper(II)-neocuproine [Cu (II) -Nc] CUPRAC, for inhibiting AChE, compound with di-μ-chloro bridged CuII was more effective than the reference medicine compound Galentamine. Magnetic measurements revealed that all of the products measured showed predominant antiferromagnetic interactions