Spectroscopic studies and DFT calculations of cimetidine complexes with transition metal ions

Abstract

The coordination behavior of the antiulcer drug cimetidine (cime) towards transition metal ions was investigated. The synthesis and characterization of [Cr(cime)2Cl2]Cl·3H2O, [Co(cime)Cl2]·5H2O, [Co(cime)3Cl]Cl·3H2O, [Ni(cime)Cl2(H2O)2]·H2O, [Cu(cime)Cl2]·2H2 O, [Cu(cime)2Cl(H2O)]Cl·H2O, [Cu(cime)3Cl2]·3H2O, [Cu2(cime)Cl4], and [Zn(cime)Cl2]·1.5H2O are discussed, where cime acts as monodentate (imidazole N3) or bidentate ligand (N3 and S8). IR, UV-vis, EPR and NMR spectroscopies, mass spectrometry (FAB+), were employed for the characterization. In order to identify the most reactive areas of cimetidine, the electrostatic potential map of the ligand was calculated; also the structures of minimum energy of the coordination compounds were modeled using DFT (B3LYP/def2-TZVP) calculations. © 2013, Sociedad Química de México.