Studies in Th(IV) complexes with some substituted pyrazolines at 0.1M ionic strength potentiometrically

The interactions of Thorium ion with 3-(2-hydroxy-5-methyl phenyl)-1, 5-diphenyl pyrazoline, 3-(2-Hydroxy-5-methyl phenyl)-1 phenyl-5-(4-methoxy phenyl) Pyrazoline and 3-(2-Hydroxy-5-methyl-phenyl)-l-phenyl-5-(3, 4-methylene dioxy phenyl)-pyrazoline have been investigated by Bjerrum method as adopted by Calvin and Wilson. The stability constants of complexes containing 1:1 and 1:2 ratios of Th(IV) to ligand have been estimated at (27 ± 0.1degC) and 0.1M ionic strength (NaClO4) in 80 per cent dioxane-water mixture. The validity of log K=apk+b relation is examined for there complexes. (author)