Study of possibility of Ac3+ reduction to Ac2+ in aqueous-ethanol solutions of bivalent samarium

Owing to controversial literature data concerning existence of actinium in oxidation state 2+ in aqueous solutions, potentiality of actinium reduction in water-ethanol solutions, where stability of bivalent form of f-elements is higher than in aqueous media, has been studied. It is shown that in the presence of bivalent samarium (E0Sm3+/Sm2+=-1.5 V) the attempts to attain the conditions sufficient for Ac(3) reduction to Ac(2) failed. The results contradict the data obtained by French and Japanese scientists on Ac2+ preparation in aqueous solutions by the method of radiopolarography. 10 refs., 2 tabs