International Science Community Association Research Journal of Chemical Sciences 2231 - 606X 4 2 2014 February 18 Spectrophotometric Method for determination of Copper (II) using p-Chlorobenzaldehyde -4-(2'-carboxy-5-sulphophenyl)-3-thiosemicarbazone [p-CBCST] 1 6 EN Patel N.C 1 Department of Chemistry, SIR P. T. Sarvajanik College of Science, Surat-395009, INDIA Patel BhaveshA 2 > Research Paper 2013 4 3 2014 February 18 p-Chlorobenzaldehyde-4-(2’-carboxy-5’-sulphophenyl)-3-thiosemicarbazone [p-CBCST] is spectrophotometric reagent for copper (II) in DMF. Reaction between metal ion and p- Chlorobenzaldehyde -4-(2’-carboxy-5’-sulphophenyl)-3-thiosemicarbazone [p-CBCST] forming a pale yellow colored complex in the pH range 3.0-4.5. The complex shows maximum absorption at 325 nm. The molar absorptivity found to be 5.137×103 lit. mol.-1 cm.-1. The complexes have been characterized on the basis of elemental analysis, UV, IR, NMR spectra. p-CBCST is found to be a selective and strong chelating agent for copper. The 1:2 metal:ligand ratio of complex found from the mole ratio and the slope ratio method and the Job’s method of continuous variation. The stability constant of the complex found to be 1.184 × 1012. Copyright@ International Science Community Association