Synthesis, characterization and anticoagulant action of lanthanide complexes of warfarin

Thirteen lanthanide complexes of warfarin, LnL(3). nH(2)O [n = 6 (Ln = La-Y b) or n = 4 (Ln = Y); L = (C19H15O4)(-)] have been synthesized and characte rized by elemental analyses, IR, H-1 NMR, thermoanalysis and molar conducta nce. The lanthanide ions combine with warfarin through the oxygen anion of the phenolic group by losing the proton and the oxygen atoms of two carbony l groups. The warfarin lanthanide complexes show good anticoagulant action, especially the warfarin neodymium complex, which was less toxic than the s odium salt of warfarin.