Structural Regulation of Two Polyoxometalate-Based Metal-Organic Frameworks for the Heterogeneous Catalysis of Quinazolinones.

Two dimeric {ε-}-based metal-organic frameworks (MOFs), [ε-PMoMoO(OH)Zn][LO] (, LO = [5-((4'-carboxybenzyl)oxy)isophthalic acid]) and [TBA][ε-PMoMoO(OH)Zn][LN] (, TBA = tetrabutylammonium ion, LN = [5-((4-carboxybenzyl)imino)isophthalic acid]), combining the advantages of polyoxometalates (POMs) and MOFs, were synthesized by the one-pot assembly strategy. The dimeric {ε-} units act as nodes that are linked by the flexible ligands and extended into two- or three-dimensional frameworks. The cyclic voltammetry and proton conductivity measurements of and were performed and indicated the high electron and proton transfer abilities. These materials also e xhibited the catalytic performance for the synthesis of quinazolinones in the heterogeneous state, and the different binding capacities toward the substrates caused the catalytic activity of to be higher than that of under the same conditions. In addition, the used catalysts could be readily recovered for five successive cycles and maintained high catalytic efficiency.