Mossbauer effect study of iron(III)-inidazolidine nitroxyl-free radical ligand complex

A new complex, [Fe(acac)L-2], bearing inidazolidine nitroxyl-free radical l igand (L-) was recently synthesised for biological studies. It proved to be biologically active against African sleeping sickness, plasmodium falcipar um (malaria), leishmaniasis and chaga disease causative agents. Three ESR w ell resolved peaks indicated the presence of a free (unpaired) and chemical ly active electron in the complex. The structural complex ferric iron was f ound at the centre of two electric gradient whose the biggest is suggested to be initiated by the unpaired charge. No distinction between different ci s isomers could be made.