Lanthanide Complexes of Ethyl Biscoumacetate and Their Anticoagulant Action

Abstract The lanthanidc complexes of ethyl biscoumacctatc (ML2C1 2H2O) have been synthesized and characterized by IR, 1H NMR, electronic spectra, thcrmoanalysis and molar conductance The metal ions substituted a lydrogen atom of an hydroxy group and are also bonded to the oxygen atom of the carbonyl group of the benzopyranyl ring. Electronic spectra showed that the lanthanidc-ligand bond had some covalent character and the involvement of 4f orbitals was very small. The light lanthanide complexes showed good anticoagulant action, expecially the lanthanum coordination compound, which was less toxic than the ligand.