The acid dissociation constant of ligands derived from S-alkyl dithiocarbazate and stability constants of their complexes with Ni(II), Cu(II) and Zn(II) metal ions in 75% ethanol-water

In this work, the dissociation constants of S-benzyldithiocarbazate (SBDTC)=L1 and S-benzyldithiocarbazate acetophenone (SBDTCAC)=L2 and the formation constants of their binary complexes with Ni(II), Cu (II) and Zn (II) were determined by potentiometric titration against 0.1 M KOH at 0.1 M KNO3 ionic strength in 75% (vv) ethanol-water. All these metal ions form 1:1 and 1:2 binary complexes. The thermodynamic parameters such as ΔG, ΔH, and ΔS of the binary complexes were determined using the Vant-Hoff equation. Conductometric technique was also used to get a complete picture on formation and behaviour of the chelates in solution.