Studies on Composition and Stability Constants of Complexes of Copper(ll) and Nickel(Il) with 2N-Salicylidene- and 2N-3,5-Dichlorosalicylidene-5-phenyl-1 ,3,4- thiadiazole Schiff Base

Government Science College, Gwalior

Manuscript received 7 March 1984, accepted 8 November 1984

The composition, protonation constants of 2N-salicylidene-5-phenyl-1,3,4-thi­adiazole and 2N-3,5-dichlorosalicylidene-5-phenyl-1,3,4-thiadiazole and formation constants of their metal-chelates with Cu^ll and Ni^ll in 50% ethanol-water system have been determined by Irving-Rossotti method at various ionic strengths at 25±1°. The observed order of the ligands on the basis of relative strength is SPT >DCSPT. The order of stability of the metal chelates is found to be Cu^ll >Ni^II. Solid comp­lexes were also separated. Chemical analyses suggest a 1 : 2 stoichiometry of metal ligand.