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Javad Zolgharnein

Javad Zolgharnein

Academic rank: Professor
ORCID: http://orcid.org/0000-0003-3889-0128
Education: PhD.
ScopusId: 6602705315
Faculty: Science
Address: Arak University
Phone:

Research

Title
Thermodynamics of Complexation of Li+ ion with Tetra-ethyleneglycolbis- (8- quinolyl)Ether in some Noneaqueous Solutions Lithium-L7 NMR Study of the
Type
JournalPaper
Keywords
-Lithium-L7 NMR- Complexation -Noneaqueous
Year
1998
Journal Journal of Coordination Chemistry
DOI
Researchers Javad Zolgharnein

Abstract

7Li, =Na and I3C NMR measurements were used to study the stoichiometry and stability of Li" and Na+ complexes with dibenzo-2eCrown-8 in binary nitromethane-acetonitrile mixtures. The resulting chemical shift-mol ratio data clearly reveal the formation of both 1 : 1 and 2: 1 (metal/ligand) complexes in solution. Formation of the two adducts in nitromethane and acetonitrile solutions was further supported by monitoring the molar conductance of Li+ and Na+ solutions as a function of macrocycle/metal ion mol ratio. Stepwise formation constants of the 1 : 1 and 2: 1 complexes were evaluated from computer fitting of the NMR mol ratio data to equations which relate observed metal ion chemical shifts to formation constants. In all solvent systems, sodium forms more stable complexes with the crown ether than lithium. There is an inverse linear relationship between the logarithms of the Stability constants and the mol fraction of acetonitrile in the solvent mixtures.