Abstract
In this article, three types of metal ions with different oxidation state as mercury(II) , cerium(III) thorium(IV) have been reacted with captopril drug (CAP). The isolated solid complexes were explained using elemental analysis, conductance measurements, infrared and H-1-NMR spectroscopy as well as the thermo gravimetric (TG/DTG) analysis. The micro analytical and spectroscopic results for all CAP complexes were agreement with the speculated structures. The stoichiometry for divalent Hg2+, trivalent Ce3+ and tetravalent Th4+ metal ions with CAP ligand was established with 1 : 2 (Mn+ : CAP) molar ratio. The qualitative analysis showed that in case of the mercury(II) complex, the chloride ions didn't involved in the complexity, suggesting formula [Hg(CAP)(2)] in neutral form. However, regarding both Ce(III) and Th(IV) complexes as [Ce (CAP)(2)(NO3)]center dot 3H(2)O and [Th(CAP)(2)(NO3)(2)( H2O)]center dot 3H(2)O formulas, the nitrate group is existed inside the coordination sphere. The infrared analysis data proved that CAP drug act as a bidentate ligand with the metal ions of Ce(III) and Th(IV) through oxygen carbonyl group C=O and oxygen of the deprotonated carboxylic COOH group, while for the Hg(II) complex, the CAP acts as a bidentate ligand through oxygen of C=O group and sulfur atom of the deprotonated -SH group. Thorium(VI) complex has a nine-coordinate geometry, while Hg(II) and Ce(III) have a four and six-coordination behaviors respectively. The H-1-NMR data of the CAP compound has a singlet sharp signal at 1. 90 ppm due to the proton of -SH group, this peak absent in the spectrum of the Hg(II) CAP complex upon the deprotonated of thiol group.