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

Two polyoxometalate-based hybrids, [M(btap) 3 (H 2 O) 3 (HPW 12 O 40 )]· x H 2 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 Co II and PW, in which the Co centers activate O 2 to ˙O 2 - and further binding of free H + from PW affords the active peroxyacid.