Coordinating Zirconium Nodes in Metal-Organic Framework with Trifluoroacetic Acid for Enhanced Lewis Acid Catalysis

摘要

Regulating Lewis acid sites with well-defined electronic state and steric environment is still challenging for achieving high catalytic efficiency.Here we show coordinating zirconium nodes in the typical metal-organic framework known as MOF-545 with the monocarboxylate modulators including trifluoroacetic acid(TFA)or benzoic acid(BA)over meso-tetra(4-carboxyphenyl)-porphine(H_(2)TCPP),denoted as MOF-545-TFA or MOF-545-BA.Impressively,MOF-545-TFA shows the significantly enhanced performance for the catalytic ring-opening reaction of various epoxides with alcohols and good recyclability at 40°C in respect with MOF-545-BA and ZrO_(2).This mainly originates from the stronger Lewis acidity and more active zirconium sites induced by the electron-withdrawing TFA,resulting in the increased ability for activation of epoxides.This modulation approach is promising for enlarging the toolbox to extend the MOFs-based Lewis acid catalysis.