LANTHANIDE COMPLEXES OF ETHYL BISCOUMACETATE AND THEIR ANTICOAGULANT ACTION

The lanthanide complexes of ethyl biscoumacetate (ML2Cl . 2H2O) have b een synthesized and characterized by IR, H-1 NMR, electronic spectra, thermoanalysis and molar conductance. The metal ions substituted a hyd rogen atom of an hydroxy group and arc also bonded to the oxygen atom of the carbonyl group of the benzopyranyl ring. Electronic spectra sho wed that the lanthanide-ligand bond had some covalent character and th e involvement of 4f orbitals was very small. The light lanthanide comp lexes showed good anticoagulant action, expecially the lanthanum coord ination compound, which was less toxic than the ligand.