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Spectroscopic, thermal analysis, and nematicidal evaluation of new mixed ligand complexes of bidentate Schiff base and 1,10 phenanthroline with some transition metals
Author(s) -
ElAttar Mohamed S.
Publication year - 2018
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201800028
Subject(s) - chemistry , denticity , ligand (biochemistry) , phenanthroline , crystallography , schiff base , transition metal , enthalpy , stereochemistry , crystal structure , organic chemistry , biochemistry , physics , receptor , quantum mechanics , catalysis
Mononuclear Co(II), Cu(II), Y(III), Zr(IV), La(III), and U(VI) complexes of 2‐[(2‐hydroxybenzylidene)‐amino]‐benzoic acid (H 2 L) ligand in presence of 1,10‐phenanthroline (Phen) were synthesized and characterized by elemental analysis, spectroscopic techniques (IR, UV–vis, and 1 H‐NMR), X‐ray powder diffraction and magnetic measurements. The results prove that H 2 L acts with the mentioned metal salts as a bidentate ON donor ligand and Phen as an NN donor ligand. The calculated bond length and force constant F (UO) in the uranyl complex are 1.732 Å and 708.90 nM −1 , respectively. The electronic spectra and the magnetic susceptibility data support the octahedral geometry for the mononuclear Co(II), Y(III), Zr(IV), La(III), and U(VI) complexes and square‐pyramidal geometry for the Cu(II) complex. Thermogravimetric analysis was performed to determine the thermal stability of the synthesized compounds. The kinetic parameters, that is, the activation energy ( E *), pre‐exponential factor ( A ), entropy of activation (Δ S *), enthalpy of activation (Δ H *) and free energy of activation (Δ G *), of the thermal degradation process were evaluated using Coats–Redfern (C–R) and Horowitz–Metzger (H–M) methods for all the complexes, and the best fit results could be obtained. In the present work, all the synthesized complexes showed nematicidal activity against the root knot nematode ( Meloidgyne javanica ) by inhibiting egg hatching and causing larval mortality of second‐stage juveniles.