Effective oxygen activation on polyoxometalate-based hybrids for epoxidation of alkenes.

Two polyoxometalate-based hybrids, [M(btap)3 (H2 O)3 (HPW12 O40 )]· x H2 O (M-PW, M = Co/Mn, btap = 3,5-bis(1',2',4'-triazol-1'-yl)pyridine) were synthesized. Co-PW exhibited higher activity and selectivity towards olefin epoxidation than Mn-PW due to the synergistic effect between CoII and PW, in which the Co centers activate O2 to ˙O2 - and further binding of free H+ from PW affords the active peroxyacid.