Abstrait

Spectrophotometric and conductometric determination of propranolol asMg(II), Pb(II), Fe(II),Mn(II) andNi(II)-dithiocarbamate complexes

Saeedeh Sepehrikiya, Zahra Sepehri, DonyaArefi1, Alireza Shams

A spectrophotometric method was developed for the determination of the beta adrenergic blocking drug propranolol. The method was based on the formation of Mg(II), Pb(II), Fe(II), Mn(II) and Ni(II)-dithiocarbamate complexes from the secondary amine group of propranolol with carbondisulfide (CS2) and the acetate salts of the metals in ammonia medium. and The interaction of the Propranolol with Pb(C2H3O2)2, Mg(CH3COO)2, Mn(CH3COO)2, C14H27Fe3O18, C4H6NiO4 in methanol has been investigated by conductometric method under equilibrium conditions1- 6. The stability constants of the complexes were determined using a GENPLOT computer program7. The conductance data and Absorbance– mole ratio plots show that in all solvent systems, the stochiometric of the complexes formed between Propranolol and Mg(II), Pb(II), Fe(II), Mn(II) and Ni(II) cations is 1:1 (M:L). The obtained results show that the stability of Mg(II)-Pr, Pb(II)-Pr, Fe(II)- Pr, Mn(II)-Pr and Ni(II)-Pr complexes is sensitive to the mixed solvents composition. The values of thermodynamic parameters (ÄGï‚°, ÄHï‚° and ÄSï‚°) for formation ofMg(II)-Pr, Pb(II)- Pr, Fe(II)-Pr, Mn(II)-Pr and Ni(II)-Pr complexes were obtained from temperature dependence of the stability constant using the vanÂ’t Hoff plots. The value of logkf calculated from the absorption spectra measurement for Mg(II)-Pr, Pb(II)-Pr, Fe(II)-Pr, Mn(II)-Pr and Ni(II)-Pr complexes at 25ÚC. The results show that the complexation formation is affected by the nature of solvents.