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Updated: May 11, 2026

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions
Published on: July 28, 2022
Bivalent transition metal complexes of cetirizine: spectroscopic, equilibrium studies and biological activity
Ahmed A El-Sherif1, Mohamed M Shoukry, Lamis O Abobakr
1Department of Chemistry, Faculty of Science, Cairo University, Giza 12613, Egypt. aelsherif72@yahoo.com
Abstract:
Metal complexes of cetirizine·2HCl (CTZ=2-[2-[4-[(4-chlorophenyl)phenyl methyl]piperazine-1-yl]-ethoxy]acetic acid, dihydrochloride have been prepared and characterized by elemental analyses, IR, solid reflectance, magnetic moment, molar conductance, and UV-Vis spectra. The analytical data of the complexes show the formation of 1:2 [M:L] ratio, where M represents Ni(II), Co(II) and Cu(II) ions, while L represents the deprotonated CTZ ligand. IR spectra show that CTZ is coordinated to the metal ions in a monodentate manner through carboxylate-O atom. Protonation equilibria of CTZ and its metal complexation by some divalent metal ions were determined in aqueous solution at constant ionic strength (0.1 M NaCl) using an automatic potentiometric technique. Thermodynamic parameters for the protonation equilibria of CTZ were calculated and discussed. The stability order of M(II)-CTZ complexes were found to obey Mn(2+)
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