Solvent Extraction Studies on Mixed-Ligand Complex Formation of Vanadium(V) with N-Cinnamoyl-N-p-Methylphenylhydroxylamine and Thiocynate Ion

Chemistry Department, Jadavpur University, Calcutta-700 032

Manuscript received 24 March 1980, revised 24 April 1981, accepted 19 May 1981

The extraction of Vanadium(V)-N-p-cinnamoyl-N-p-methylphenylhydroxylamine(l) complex in the presence of thiocyanate into chloroform may be used for the spectro-photometric determination of vanadium in the presence of various diverse ions and also in steel samples. The extracted species, 1 : 2: 1 V(V)-I-SCN complex, shows an absorption maximum at 590 nm with a molar absorptivity of 6.9 x 10³. Marked synergism is noted during the above extraction. The synergistic role of thiocyanate in the mixed ligand complexation has been utilized in the present work for the evaluation of the composition of the complex where both Job's and molar ratio methods are inapplicable. By extending the absorptiometrie method the different equilibrium extraction constants (K_ex, K_A and K_mixed) have been evaluated.