Editor-in-Chief Hatice Kübra Elçioğlu Vice Editors Levent Kabasakal Esra Tatar Online ISSN 2630-6344 Publisher Marmara University Frequency Bimonthly (Six issues / year) Abbreviation J.Res.Pharm. Former Name Marmara Pharmaceutical Journal
Marmara Pharmaceutical Journal 1992 , Vol 8 , Issue 2
The determination of stability constants of N-salicylidene-L-asparagine chromium, manganese, iron, cobalt, nickel, copper and zinc complexes by potentiometric method
Hülya Demircan,Emre Dölen
The stability constants of the complexes were formed N-salicylidene-L-asparagine with chromium (III), manganese (II), iron (II), cobalt(II), nickel (II), copper(II) and zinc(II) were determined potentiometrically by using CALVIN- BJERRUM and IRWING-ROSSOTTI methods, in this work. The protonation constants or dissocation constants of the ligand were found as log K1 or pK4= 9,9 ; as log K2 or pK3 = 8,6; as log K3 or pK2 = 3,0; as log K4 or pK1= 2,3 at 25°C and for I= 0,11. Also the overall formation constants of complexes were found as log β2 = 28,15 for chromium (III) ; as log β2 =20,45 for manganese(II) ; as logβ2 = 18,85 for iron(II); as log β2 =24,5 for iron(III) ; as logβ2=18,1 for cobalt(II); as logβ2 = 10,35 for nickel(II); as log β2 = 14,15 for copper(II); as logβ2 = 11,7 for zinc(II) at 25°C and for I= 0,11. The conditional formation constants and the formation pH ranges of complexes were determined. The composition of metal complexes were determined as metal/ligand = ½, except for copper and nickel complexes. The composition of copper and nickel complexes were determined as metal/ligand = 1/1 Keywords :
Marmara University