<b>PREPARATION, SPECTROSCOPIC STUDIES AND X-RAY STRUCTURE OF HOMOBINUCLEAR LANTHANIDE(III) COMPLEXES DERIVED FROM 2,6-DIFORMYL-4-CHLOROPHÉNOL-BIS-(2'-HYDROXY-BENZOYLHYDRAZONE)</b>

Abstract

ABSTRACT. Reaction of the 2,6-diformyl-4-chlorophenol-bis-(2'-hydroxy-benzoylhydrazone) with Ln(NO3)3.nH2O (n = 5 or 6 and Ln = Y, La, Ce, Pr, Nd, Sm, Gd, Dy, Er and Yb) produces homobinuclear complexes. These complexes have been characterized by analysis, molar conductance, magnetic measurements, infrared spectral studies and X-ray diffraction. The analytical data showed 1:3 (metal:ligand) stoichiometry. Molar conductance measurements in dmf indicate 1:3 electrolytes in all cases. Magnetic moment values are close proximity of the Van Vleck values. IR studies suggest the coordination of the ligand is through the azomethine, the phenolic oxygen atom and the carbonyl oxygen of the hydrazonic moiety. The nitrate ion is also found to be ionic in all the complexes. An X-ray structure determination of [C66H48N12O15Cl3Er2]Cl2NO3.5H2O confirms the conclusion from the spectroscopic studies and show that the erbium is at the centre of a tricapped trigonal prism with coordination number nine. In all the complexes the lanthanide ions have substantially similar coordination.

Preparation, Characterization of Some Lanthanide(III) Complexes of N'-(phenyl(pyridin-2-yl)methylene)nicotinohydrazide

“…These complexes are particularly interesting in various fields such as magnetism [6], catalysis [7], in medicine [8], and luminescence [9,10]. The presence of phenolic moiety suggests that these complexes can be antioxidants as reported in the literature [11] but also as antibacterial agents [12,13]. In recent studies, nicotinic hydrazide complexes were prepared and showed enzyme-like activities [14,15].…”

“…In addition to these signals, two singlets are identified at 8.73 and 9.01 ppm and each integrating a proton attributed respectively to the proton H15 and that of NH [21]. The 13 C NMR spectrum indicates the signal of the carbon of the carbonyl function (C=O) at 160.10 ppm and that of the carbon of the imine function (C=N) at 148.91 ppm [9,11]. The signal in the range 123.10-148.34 are assigned to the aromatic carbon atoms.…”

“…La1-O1 2.505 (3) O1 i -La1-N2 i 58.79 (10) La1-O1 i 2.505 (3) O1-La1-N2 i 105.05 (11) La1-O2 i 2.730 (4) O1 i -La1-N2 105.06 (11) La1-O2 2.730 (4) O1-La1-N2 58.79 (10) Preparation, Characterization of Some Lanthanide(III) Complexes ……”