A polyoxometalate-embedded Cu-triazole cycle: catalytic oxidation of alcohols

Abstract

In the present study, a novel three-dimensional (3D) porous framework, [Cu^I₃Cu^II₄Cl(TRZ)₇][GeW₁₂O₄₀]·7H₂O, designated as Cu-W-TRZ, was synthesized through a hydrothermal approach by integrating the {GeW₁₂} cluster into a Cu(I/II)-TRZ framework. This material exhibited remarkable catalytic activity in the oxidation of alcohols. Under optimized conditions, it achieved high substrate conversion rates (surpassing 99%) and selectivity (surpassing 99%). The excellent catalytic performance of Cu-W-TRZ can be ascribed to the synergistic interaction between the Cu(I/II) sites and the {GeW₁₂} cluster in multifunctional catalysis. The abundant Cu ions act as active sites to activate the O–O bond of TBHP, resulting in the generation of tert-butyl oxygen (t-BuO˙) radical species. Moreover, the incorporation of the {GeW₁₂} cluster promotes proton coupling, enhancing the Brønsted basicity of the material and facilitating the smooth progress of the reaction.