CATALYTIC BEHAVIOR OF A SERIES OF LANTHANIDE DECATUNGSTATES [LN(III)W10O369-, LN = LA-YB] FOR H2O2-OXIDATIONS OF ALCOHOLS AND OLEFINS - SOME CHEMICAL EFFECTS OF THE 4F(N)-ELECTRON IN THE LANTHANIDE(III) ION ONTHE CATALYZES

The catalytic activities of a series of lanthanide decatungstates [Ln( III)W10O369-; Ln(III)W10, Ln: La-Yb] modified with cetylpyridinium cat ions for H2O2-oxidation of both cyclooctene to epoxycyclooctane and be nzyl alcohol to benzaldehyde were investigated in a CHCl3-aqueous H2O2 biphasic system. The activity for the former reaction decreased almos t linearly along with the contraction of the Ln(III) ion in Ln(III)W10 , and on the contrary, that for the latter tended to increase. The act ivity for the alcohol correlated, additionally, with the physicochemic al parameters of Ln(III)10. A chemical effect of the 4f ''-electrons i n the lanthanide(III) ion on such catalytic behavior will be discussed from a mechanistic viewpoint. (C) 1997 Elsevier Science S.A.