Journal :   Asian Journal of Research in Chemistry

Volume No. :   4

Issue No. :  12

Year :  2011

Pages :   1908-1914

ISSN Print :  0974-4169

ISSN Online :  0974-4150


Registration

Allready Registrered
Click to Login

Chemical Speciation of Ternary Complexes of Co (II), Ni (II) and Cu (II) With L-Histidine and L-Glutamic Acid in Low Dielectric Media



Address:   S. Raju, B. Ananda Kumar, K. B. K. Naik and G. Nageswara Rao*
Department of Inorganic and Analytical Chemistry, School of Chemistry, Andhra University, Visakhapatnam, Pin Code: 530 003, India.
*Corresponding Author
DOI No:

ABSTRACT:
Chemical speciation of ternary complexes of Co(II), Ni(II) and Cu(II) with L-histidine and L-glutamic acid was studied in various concentrations (0-60% v/v) of DMSO-water mixtures maintaining an ionic strength of 0.16 mol L-1 (NaCl) at 303.0 K. Alkalimetric titrations were carried out in different relative concentrations (M: L: X = 1:2.5:2.5, 1:2.5:5.0, 1:5.0:2.5) of metal (M) to histidine (L) to glutamic acid (X) with sodium hydroxide as titrant. Stability constants of ternary complexes were calculated and various models were refined with MINIQUAD75. The trend of the variation in the stability constants with changing dielectric constant of the medium was explained based on the electrostatic interactions of the side chains of the ligands, charge neutralization, chelate effect, stacking interactions and hydrogen bonding. The species detected are MLXH, MLX2H and MLX2 for Ni(II) and Cu(II) and MLX2H and MLX2 for Co(II). Distribution diagrams with pH at different compositions of DMSO and structures of plausible ternary complexes were also presented.
KEYWORDS:
Ternary complexes, chemical speciation, stability constants, DMSO, essential metals.
Cite:
S. Raju, B. Ananda Kumar, K. B. K. Naik, G. Nageswara Rao. Chemical Speciation of Ternary Complexes of Co (II), Ni (II) and Cu (II) With L-Histidine and L-Glutamic Acid in Low Dielectric Media. Asian J. Research Chem. 4(12): Dec., 2011; Page 1908-1914.
[View HTML]      [View PDF]



Visitor's No. :   126925