A Thermodynamic Study of Complex Formation between 15-Crown-5 with Mg2+, Ca2+, Sr2+ and Ba2+ in Acetonitrile Methanol Binary Mixtures Using Conductometric Method
Department of Chemistry, Faculty of Science Ferdowsi University of Mashhad, Mashhad, I.R. IRAN
10.30492/ijcce.2001.9974
Abstract
The complexation reactions between Mg2+, Ca2+, Sr2+ and Ba2+ metal cations with 15-crown-5 (15C5) were studied in acetonitrile (AN)-methanol (MeOH) binary mixtures at different temperatures using conductometric method. 15C54 forms 1:1 complexes with Mg2+, Ca2+ and Sr2+ cations in solutions. The Ma2+ cation forms a 2:1 complex (ratio of lighand to cation) in solutions. A linear relation was observed for variation of logKf of 15C5-Ca2+ and 15C5-Sr2+ complexes vs the composition of An-MeOH binary systems, but a non-linear behavior was observed in the case of 15C5-Mg2+ complex in these binary mixtures. Selectivity of 15C5 for Mg2+, Ca2+ and Sr2+ cations is sensitive to solvent composition. In some cases and in certain compositions of the mixed solvent systems, the selectivity order is changed. The values of thermodynamic parameters (DH0c , DS0c ) for formation of 15C5-Mg2+ , 15C5-Ca2+ and 15C5-Sr2+ complexes were obtained from temperature dependence of stability constants and the results show that the thermodynamics of complexation reactions is affected by the nature and composition of the mixed solvents.
Rounaghi, G. H., & Sanavi Khoshnood, R. (2001). A Thermodynamic Study of Complex Formation between 15-Crown-5 with Mg2+, Ca2+, Sr2+ and Ba2+ in Acetonitrile Methanol Binary Mixtures Using Conductometric Method. Iranian Journal of Chemistry and Chemical Engineering, 20(2), 82-89. doi: 10.30492/ijcce.2001.9974
MLA
Gholam Hossein Rounaghi; Raziyeh Sanavi Khoshnood. "A Thermodynamic Study of Complex Formation between 15-Crown-5 with Mg2+, Ca2+, Sr2+ and Ba2+ in Acetonitrile Methanol Binary Mixtures Using Conductometric Method". Iranian Journal of Chemistry and Chemical Engineering, 20, 2, 2001, 82-89. doi: 10.30492/ijcce.2001.9974
HARVARD
Rounaghi, G. H., Sanavi Khoshnood, R. (2001). 'A Thermodynamic Study of Complex Formation between 15-Crown-5 with Mg2+, Ca2+, Sr2+ and Ba2+ in Acetonitrile Methanol Binary Mixtures Using Conductometric Method', Iranian Journal of Chemistry and Chemical Engineering, 20(2), pp. 82-89. doi: 10.30492/ijcce.2001.9974
VANCOUVER
Rounaghi, G. H., Sanavi Khoshnood, R. A Thermodynamic Study of Complex Formation between 15-Crown-5 with Mg2+, Ca2+, Sr2+ and Ba2+ in Acetonitrile Methanol Binary Mixtures Using Conductometric Method. Iranian Journal of Chemistry and Chemical Engineering, 2001; 20(2): 82-89. doi: 10.30492/ijcce.2001.9974
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