Abstract
Metal-organic frameworks (MOFs) composed of infinite metal units exhibit enhanced electron transport and charge migration capabilities compared to discrete metal units. Herein, three underdeveloped isomorphic MOFs featuring 3D infinite zinc units are designed and synthesized. The Lewis acidity and photocatalytic activity of these MOFs are fine-tuned through atomic-level engineering of nitrogen atoms of ligands and the resultant change of charge transfer modes. These MOFs are promising catalysts in the photocatalytic monooxygenation of sulfenamides with molecular oxygen. Mechanistic investigations suggest that the uneven charge distribution and large dipole moment at the pyridine center of 1-PTB and the infinite Zn unit frameworks of degenerate energy levels are key to its excellent photocatalytic activity.