Fig. 5: Mechanistic investigation.
From: Metal-organic framework boosts heterogeneous electron donor–acceptor catalysis
a UV-vis spectra of 4a, Zr-PZDB, and their mixture in DMSO (5 × 10−4 M); a. u. = absorbance units. b UV-vis spectra of 4a, PZDB-H, and their mixture in DMSO (5 × 10−4 M); a. u. = absorbance units. c Radical capture and clock experiments. d, e Light on/off experiments for coupling reactions of 1a/THF (d) and 4a/pyrrole (e). f HRMS spectrum of crude reaction mixture catalyzed by PZDB-Me. g Zoom-in 1H NMR of digested Zr-PZDB as prepared (up) and after catalytic reaction (down). h, i Proposed reaction mechanisms for Minisci-type reaction (h) and pyrrole arylation (i).
