A novel Ti–O–Ti bonding species constructed in a metal-oxide cluster [{Ti(OH2)(ox)}2(μ-O)(α-PW11O39)]5− as a precatalyst: Epoxidation of alkenes with hydrogen peroxide

A novel Ti–O–Ti bonding complex constructed in the monomeric, mono-lacunary α-Keggin polyoxotungstate, [{Ti(OH2)(ox)}2(μ-O)(α-PW11O39)]5− (1) can act as a precatalyst for the epoxidation of cyclooctene, cyclohexene, and 1-octene with aqueous H2O2 at 25 °C in a homogeneous system. The catalytic activities of complex 1 were considerably higher than those of dimeric mono-, di-, and tri-titanium(IV)-substituted Keggin polyoxotungstates [(α-PTiW11O39)2O]8− (2), [(α-1,2-PW10Ti2O38)2O2]10− (3), and [(α-1,2,3-PTi3W9O37)2O3]12− (4).

Graphical abstractA novel Ti–O–Ti bonding complex constructed in the monomeric, mono-lacunary α-Keggin polyoxotungstate, [{Ti(OH2)(ox)}2(μ-O)(α-PW11O39)]5− (1) can act as a precatalyst for the epoxidation of cyclooctene, cyclohexene, and 1-octene with aqueous H2O2 at 25 °C in a homogeneous system. The catalytic activities of complex 1 were considerably higher than those of dimeric mono-, di-, and tri-titanium(IV)-substituted Keggin polyoxotungstates. Figure optionsDownload full-size imageDownload as PowerPoint slide