Understanding the structural features governing the optoelectronic properties of Metal-Organic Frameworks (MOFs) is crucial for their widespread application in technologies necessitating efficient charge transport, including energy storage and conversion. To this end, increasing the dimensionality of the secondary building units (SBUs) in MOFs can enhance electronic interactions between their constituent atoms, potentially leading to efficient charge transport properties. This approach could give rise to multi-functional materials combining the distinctive properties of different material classes, such as MOFs' porosity and tunability, with the optoelectronic characteristics observed in layered inorganic materials (e.g., metal oxides). In this context, we used the underexplored di-pyrogallol ligand to design a MOF featuring a two-dimensional (2D) SBU, comprising mixed-valent Fe2+ and Fe3+ metal ions bridged by oxygen atoms. The spatial arrangement of the iron sites within the 2D SBU facilitates strong electronic interactions between them. Our study underscores the advantages of MOFs featuring high-dimensional SBUs and can serve as a blueprint for designing novel framework structures exhibiting properties akin to those of inorganic layered materials.
