Investigation of the Spectral and Thermal Properties of Calcium and Strontium Metal Halides Complexes of Schiff base ligand


P. Selvakumar and P. Satheesh Kumar – Assistant Professors
Chemistry, Dr.N.G.P Institute of Technology, Coimbatore, Tamilnadu, India.


The condensation of 2-chlorobenzaldehyde and thiosemicarbazide in acetic acid medium leads to the formation of 2-chlorobenzaldenethiosemicarbazone. The 2-chlorobenzaldenethiosemicarbazone ligand acts as a bidendate ligand and co-ordinates with metals like calcium and Strontium . The shift to lower frequency of C=N as well as C=S vibrations in the FT-IR spectrum of the complexes compared to that of the ligand indicates that the metal co-ordination occurs at both N and S. Further, the 1H-NMR spectrum of the complex [CaBr2(Cl-btsc)] shows that the tautomerism between thione and thiol has occured during the coordination. The 2-chlorobenzaldenethiosemicarbazone calcium bromide and Strontium chloride complexes have been found to exhibit higher NLO efficiencies compared with that of the reference sample urea pellet. The DTG thermogram of the complex [CaBr2(Cl-btsc)] is observed that there is only one strong peak at temperature 314C. The complex decomposes almost completely at this temperature.