부산대학교 도서관

Functionalized metal–organic frameworks have recently received significant attention in heterogeneouscatalysis applications due to their high catalytic activity. In this work, a sulfate-functionalized Hf-clusterbasedmetal–organic framework was prepared via sulfation of a Hf-MOF, named Hf-BTC, constructed byHf6 clusters and 1,3,5-tricarboxylate linkers. The Hf-BTC-SO4 material was consequently demonstrated tobe an efficiently reusable superacid catalyst for a one-pot three-component reaction of pyrimido[1,2-a]benzimidazoles synthesis. The reaction catalyzed by the sulfated Hf-BTC could be carried out under mildand solvent-free conditions and give superior performance in a wide range of substrates. According todetailed investigation, the good catalytic performance of the sulfated-functionalized MOF likely originatesfrom the high-porosity framework and the high active sites of the functionalized clusters. Importantly, the catalyst could be easy to recover and reuse the functionalized framework several timeswith minor changes in catalytic efficiency.