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

Two dimeric {e-Zn4PMo12}-based metal-organic frameworks (MOFs), [e-(PMo8Mo4O34)-Mo-V-O-VI(OH)(6)Zn-4][LO] (SDUT-21, LO = [5((4'-carboxybenzyl)oxy)isophthalic acid]) and [TBA](3)[e- (PMo8Mo4O37)-Mo-V-O-VI(OH)(3)Zn-4][LN] (SDUT-22, 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 {e-Zn4PMo12} units act as nodes that are linked by the flexible ligands and extended into two-or threedimensional frameworks. The cyclic voltammetry and proton conductivity measurements of SDUT-21 and SDUT-22 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 SDUT-21 to be higher than that of SDUT-22 under the same conditions. In addition, the used catalysts could be readily recovered for five successive cycles and maintained high catalytic efficiency.

Automated summary

Two dimeric {e-Zn4PMo12}-based metal-organic frameworks (MOFs) were synthesized and showed high electron and proton transfer abilities, as well as catalytic performance.