Spectrophotometric study of Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Hg(II) complexes with isatin- β-thiosemicarbazone

The composition and stability of the complexes of isatin-b-thiosemicarba­zone with Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Hg(II) have been investigated us­ing spectrophotometric method at 30 °C and constant ionic strength of 0.1 mol dm-3 (KNO3) in 70 % ethanol. Experimental results indicate the formation of MeL and MeL2 complexes for Ni(II) and Co(II), and MeL for Cu(II), Zn(II), Pd(II) and Hg(II) complexes, whose stability constants, bn, have been calculated using a com­puteri­zed iterative method of successive approximation.