Coumarin derivatives: Synthesis and cation binding properties

Abstract

Coumarin derivatives were easily prepared starting from 7-hydroxy 4-methyl-2H-chromen-2-one with 40% formaldehyde and suitable secondary amines in 95% ethanol in rather good yield. The structures of all compounds were confirmed via spectroscopic techniques IR, 1H NMR, 13C NMR, mass spectra and elemental analysis. The complexing properties of the coumarin derivatives toward alkali metal, alkaline earth metal, some transition metals and some heavy metal cations have been investigated in methanol by means of UV spectrophotometry absorption and conductivity methods. Thus, the stoichiometry of the complexes formed and their stability constants were determined.