کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1234592 | 968832 | 2008 | 13 صفحه PDF | دانلود رایگان |
4,6-Diacetylresorcinol (DAR) serves as precursor for the formation of different hydrazone ligands, which are di-, tetra- or hexa-basic with two symmetrical sets of O2N tridentate, O2N2 tetradentate or O4N2 hexadentate chelating sites. The condensation of 4,6-diacetylresorcinol (DAR) with oxalyldihydrazine (ODH), in the molar ratio 1:1 and 1:2, yields the corresponding hydrazone, H6La and H4Lb, ligands, respectively. The structures of these ligands were elucidated by elemental analyses and IR, mass, 1H NMR and UV–vis spectra. Reactions of the hydrazone ligands with cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), iron(III) and chromium(III) ions in 1:2 molar ratio afforded the corresponding transition metal complexes. A variety of binuclear transition metal complexes were obtained in its di-, tetra- or hexa-deprotonated forms. The structures of the newly prepared complexes were identified by elemental analyses and IR, UV–vis, mass, 1H NMR and ESR spectra, as well as, magnetic susceptibility measurements and thermal gravimetric analysis (TGA). The bonding sites are the azomethine and CO oxygen atoms in either keto or enol forms and amino nitrogen atoms, and phenolic oxygen atoms. The metal complexes exhibit different geometrical structures such as tetrahedral and octahedral arrangements.
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 69, Issue 3, March 2008, Pages 757–769