pH-Metric Studies of Cu(II) and Th(IV) Complexes with Pyrazolines and Pyrazoles

Abstract

The interaction of Cu(lI) and Th(IV) with 1-(3-chlorophenyl)-3-(2-
hydroxy-5-methylphenyl)-5-phenylpyrawline (1), 1-(3-chlorophenyl)-3-
(2-hydroxy-3-bromo-5-methylphenyl)-5-phenyl- pyrawline (2) and
1-( 3-pheny Isulphony 1)-3-(2-hydroxy -3-bromo-5-methylphenyl)-5-( 4-methoxyphenyl)
pyrazole (3) have been investigated by Bjerrum method as
adopted by Calvin and Wilson. The stability constants of complexes of
Cu(lI) and Th(IV) have been studied at constant temperature (27 ± 0.1°C)
and 0.1 M ionic strength in 70% DMF-water mixture. It was observed that
as the colour changes from light brown to darker shade there is complex
formation between ligand and metal ion.