Abstract Metal–organic frameworks (MOFs) with mobile charges have attracted significant attention due to their potential applications in photoelectric devices, chemical resistance sensors, and catalysis. However, fundamental understanding of the charge transport pathway within the framework and the key properties that determine the performance of conductive MOFs in photoelectric devices remain underexplored. Herein, we report the mechanisms of photoinduced charge transport and electron dynamics in the conductive 2D M−HHTP (M=Cu, Zn or Cu/Zn mixed; HHTP=2,3,6,7,10,11‐hexahydroxytriphenylene) MOFs and their correlation with photoconductivity using the combination of time‐resolved terahertz spectroscopy, optical transient absorption spectroscopy, X‐ray transient absorption spectroscopy, and density functional theory (DFT) calculations. We identify the through‐space hole transport mechanism through the interlayer sheet π–π interaction, where photoinduced hole state resides in HHTP ligand and electronic state is localized at the metal center. Moreover, the photoconductivity of the Cu−HHTP MOF is found to be 65.5 S m−1, which represents the record high photoconductivity for porous MOF materials based on catecholate ligands.
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Host–Guest Interactions and Redox Activity in Layered Conductive Metal–Organic Frameworks
This paper describes the identification of specific host–guest interactions between basic gases (NH3, CD3CN, and pyridine) and four topologically similar 2-dimensional (2D) metal–organic frameworks (MOFs) comprising copper and nickel bis(diimine) and bis(dioxolene) linkages of triphenylene-based ligands using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance spectroscopy (EPR), and powder X-ray diffraction (PXRD). This contribution demonstrates that synthetic bottom-up control over surface chemistry of layered MOFs can be used to impart Lewis acidity or a mixture of Brønsted and Lewis acidities, through the choice of organic ligand and metal cation. This work also distinguishes differences in redox activity within this class of MOFs that contribute to their ability to promote electronic transduction of intermolecular interactions. Future design of structure–function relationships within multifunctional 2D MOFs will benefit from the insights this work provides.
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- PAR ID:
- 10192316
- Date Published:
- Journal Name:
- Chemistry of Materials
- ISSN:
- 0897-4756
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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