Open AccessSynthesis and spectroscopic characterization of some lanthanide(III) nitrate complexes of 3-[3-carboxyethyl-4,5- dimethylthiophene-2-yl)azo]pent-2,4-dione
Author(s) -
Janardhanan Chempakam Athira,
Y. Sindhu,
Susamma Mathunni Sujamol,
K. Mohanan
Publication year - 2011
Publication title -
journal of the serbian chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.227
H-Index - 45
eISSN - 1820-7421
pISSN - 0352-5139
DOI - 10.2298/jsc100414025a
Subject(s) - chemistry , acetylacetone , lanthanum , lanthanide , ligand (biochemistry) , cerium , deprotonation , praseodymium , inorganic chemistry , yttrium , medicinal chemistry , organic chemistry , ion , biochemistry , receptor , oxide
3-[3-Carboxyethyl-4,5-dimethylthiophene-2-yl)azo]pent-2,4-dione was synthesized by coupling diazotized 2-amino-3-carboxyethyl- 4,5-dimethylthiophene with acetylacetone. Based on various spectral studies and elemental analysis, an intramolecularly hydrogen bonded azoenol structural form was assigned for the ligand. This ligand is versatile in forming a series of lanthanide(III) complexes viz, lanthanum(III), cerium(III), praseodymium(III), neodymium(III), samarium(III) and gadolinium(III), which were characterized through various spectral studies, elemental analysis, magnetic susceptibility measurements, molar conductance and thermal analysis. The spectral data revealed that the ligand acted as a neutral tridentate, coordinating to the metal ion through one of the azo nitrogen atoms, the ester carbonyl and the enolic oxygen of the acetylacetone moiety, without deprotonation. Molar conductance values adequately supported their non-electrolytic nature. The ligand and lanthanum(III) complexes were subjected to X-ray diffraction studies. In addition, the lanthanum(III) complex underwent a facile transesterification reaction on refluxing with methanol for a long period. The thermal behavior of the lanthanum(III) complex was also examined.