Abstract
Adrenaline complexes with bivalent ions Mg2+, Ca2+, Sr2+ and Ba2+ in methanol at 60 degrees C were prepared. The prepared complexes were isolated and characterized using elemental analyses, conductivity measurements, mid infrared, Raman laser, UV-Vis., H-1-NMR spectra, X-ray powder diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDX). Upon the spectroscopic, conductivity and elemental analyses, the stoichiometric reactions indicated 1:2 (M:L) for Ca2+, Sr2+ and Ba2+ complexes [Ca(Adr)(2)(H2O)(2)](H2O)(4)Cl-2, [Sr(Adr)(2)(H2O)(2)]Cl-2 and [Ba(Adr)(2)(H2O)(6)]Cl-2 while the molar ratio of 1:1 (M:L) for Mg2+ with a formula [Mg-2(Adr)(2)(H2O)(7)]Cl-4. The interpretation of Raman and infrared spectra confirmed the coordination mode, which was through the two-catechol moiety OH phenolic groups. The in vitro antibacterial activity of adrenaline chelates that have been tested against three gram-positive bacteria, two gram-negative bacteria, and two strains of fungus showed that antimicrobial activity of the metal chelates are more effective than the adrenaline free ligand.