Expansion of the Chemical Space in UiO-Type Metal–Organic Frameworks via the Ugi Four-Component Reaction for Tuned Pore Accessibility

C NMR spectroscopy. The Ugi-derived functionalization systematically modulates porosity and pore environment, which was further tuned through a multivariate (MTV) mixed-linker strategy. Nitrogen adsorption analysis reveals systematic modulation of surface area and pore accessibility with increasing functionalization. The prepared MOFs were used to adsorb catechol, a prototypical phenolic pollutant, which was quantified by HPLC. The MTV material exhibited the highest uptake, highlighting the interplay between pore accessibility and host-guest interactions, where excessive functionalization hinders adsorption. Overall, this work establishes multicomponent reactions as a versatile platform for tuning pore chemistry in MOFs while emphasizing the need to balance functionality to optimize performance.