Comparative photocatalytic efficiency of oxotitanium(IV) phthalocyanines for the oxidation of 1-hexene

The comparative photocatalytic activities of aryloxy and arylthio tetrasubstituted oxotitanium(IV) phthalocyanine complexes for the oxidation of 1-hexene in DCM are reported for the first time. The singlet oxygen quantum yield, photostability and photocatalytic properties are investigated. The catalysts effectively catalyse 1-hexene to 1,2-epoxyhexane and 1-hexen-3-ol as major and minor products respectively. The photooxidation products are formed via two reaction mechanisms, namely via singlet oxygen (Type II) and radical (Type I) reaction pathways. These are also dependent on the singlet oxygen quantum yields and photostabilities of the phthalocyanines. Complex 1a that is peripherally substituted with phenoxy groups exhibited the best activity in terms of overall performance.

Oxotitanium(IV) phthalocyanine complexes photocatalyse the transformation of 1-hexene giving 1,2-epoxyhexane and 1-hexen-3-ol through Types II and I mechanisms. Figure optionsDownload as PowerPoint slide