Thermal and spectroscopic characterization of Pd [II] and Pt [IV] thiobarbiturate complexes

ABSTRACT

Pd [II] and Pt [IV] thiobarbiturate complexes [Ligaud 2-thiobarbituric acid; Abbreviation, HTBA] were synthesized as solid phases. Chemical and thermogravimetric analyses, together with IR and electronic absorption spectra of the ligand and the two complexes were carried out. IR vibrational bands support M-S and M-N bondings in the Pd [II] and Pt [IV] ions are tetra-and hexa-coordinated, as deduced from their electronic absorption bands characteristic of square planar and octahedral configurations, respectively. Results of thermogravimetric analysis were in agreement with the general molecular formulae Pd [TBA]2 and Pt [TBA]4 [HTBA]2 proposed by chemical analysis. The TG and DTG curves of both the Pd [II] complex and the Pt [IV] complex showed three thermal dissociation steps ending with a final step at>790 and >772 omicron, respectively. The thermal stability of the studied compounds was found to have the order Pt [TBA]4 [HTBA]2> HTBA>pd [TBA]2