Applying a Nanoparticle@MOF Interface To Activate an Unconventional Regioselectivity of an Inert Reaction at Ambient Conditions

Abstract

Here we design an interface between a metal nanoparticle (NP) and a metal–organic framework (MOF) to activate an inert CO2 carboxylation reaction and in situ monitor its unconventional regioselectivity at the molecular level. Using a Kolbe–Schmitt reaction as model, our strategy exploits the NP@MOF interface to create a pseudo high-pressure CO2 microenvironment over the phenolic substrate to drive its direct C–H carboxylation at ambient conditions. Conversely, Kolbe–Schmitt reactions usually demand high reaction temperature (>125 °C) and pressure (>80 atm). Notably, we observe an unprecedented CO2 meta-carboxylation of an arene that was previously deemed impossible in traditional Kolbe–Schmitt reactions. While the phenolic substrate in this study is fixed at the NP@MOF interface to facilitate spectroscopic investigations, free reactants could be activated the same way by the local pressurized CO2 microenvironment. These valuable insights create enormous opportunities in diverse applications including synthetic chemistry, gas valorization, and greenhouse gas remediation.

In Situ Monitoring of Hydrogen Peroxide Released from Living Cells Using a ZIF-8-Based Surface-Enhanced Raman Scattering Sensor

“…The SERS intensity of para-aminothiophenol ( p -ATP) at 1078 cm –1 slightly decreased by about 9% with the growth time extended to 3 h (Figure C). This may be caused by the weak light adsorption of the thin ZIF-8 layer, although it is almost nontransparent. , For the sake of a high efficiency, we chose 2 h as the growth time. N 2 adsorption and desorption isotherms indicated that the BET surface area of pure ZIF-8 crystals prepared using the above conditions was 1182 cm 2 ·g –1 with a pore diameter of around 0.5 nm (Figure S5), which is in accordance with the previous studies. , …”

“…It was also observed that objects themselves did not cause significant changes to the SERS sensor (Figure S12B). However, when using AuNPs@2-MHQ, the signal responding to H 2 O 2 decreased in varying extents (Figure F and Figure S12C), which may be caused by the effect of “protein corona,” the rapid adsorption of biomolecules on the metal nanoparticle surface, , thus blocking the access of H 2 O 2 . In comparison, AuNPs@2-MHQ@ZIF-8 exhibited a desirable size exclusion effect on macromolecules, which could minimize signal interference from the complex environment, such as growth media, biological liquids, and so on.…”

“…A metal–organic framework (MOF), an emerging crystalline porous material, has been integrated with plasmonic nanostructures to create rational MOF-based SERS methods, which have made great achievements in various applications, such as driving and monitoring reactions, analytical chemistry, and bioimaging. − Based on the large surface area and size exclusion effect of a MOF, it can enhance the adsorption of molecules onto the substrate surface in a selective way. For example, MOF-coated gold superparticles have been employed to capture aldehydes with a low limit of detection (10 ppb level) .…”

Emergent electrochemical functions and future opportunities of hierarchically constructed metal–organic frameworks and covalent organic frameworks

“…biology. [166][167][168][169][170][171][172] Then the knowledge acquired at the model systems would be transferred to practical technologies, for example as a high volumetric energy density cathode for battery electric vehicles (EVs), ultralow-overpotential electrocatalysts for electrolysers and fuel-cell EVs, as this approach is quite successful in the solid/gas heterogeneous catalysis, 173,174 if the chemical stability issue is solved. Because MOFs/COFs are two of the most complicated classes of electrode materials, model electrochemical systems based on the two material classes are still necessary to unveil microscopic electrode processes shown by these materials, and obtain reliable pictures.…”

Tailoring Heterogeneous Catalysts at the Atomic Level: In Memoriam, Prof. Chia-Kuang (Frank) Tsung

“…This result suggests that previous examples of activation in NP@MOF systems could be attributed to such pseudo high-pressure microenvironments. Indeed, they later built on this work to demonstrate the activation of an inert CO 2 carboxylation reaction . A Kolbe–Schmitt reaction, which usually requires high temperature (>125 °C) and pressure (>80 atm), was chosen as a model system.…”