Synthesis, Spectroscopic, and Biological Assessments on Some New Rare Earth Metal Adrenaline Adducts

Abstract

Adrenaline (Adr) reacts with chlorides of Y3+, Ce3+, Nd3+ and Sm3+ in methanol at 60 °C to yield metal ion adducts of definite composition. These compounds are characterized by elemental analyses, molar conductivity, UV-Vis., 1H–NMR, Raman laser, scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX), and mid infrared spectral measurement investigations. The adducts are found to have the formulae [Y2(Adr)2(H2O)8]Cl3.8H2O, [Ce(Adr)2(H2O)2]Cl3.10H2O, [Nd(Adr)2(H2O)2]Cl3.6H2O, and [Sm(Adr)2(H2O)2]Cl3.12H2O, respectively. The two phenolic groups of the catechol moiety are linked to central metal ions based on the infrared and Raman laser spectra. The new compounds were tested against five gram-positive and two-gram negative bacteria, in addition to two Aspergillus strains. Metal adducts were shown to have stronger antibacterial and antifungal properties than free adrenaline compounds.

Keywords

• adrenaline
• rare earth metals
• complexes
• mid infrared
• Raman laser
• biological activity