An Electrically Conducting Three-Dimensional Iron-Catecholate Porous Framework

We report the synthesis of a unique cubic metal-organic framework (MOF), Fe-HHTP-MOF, comprising hexahydroxytriphenylene (HHTP) supertetrahedral units and Fe^III ions, arranged in a diamond topology. The MOF is synthesized under solvothermal conditions, yielding a highly crystalline, deep black powder, with crystallites of 300-500 nm size and tetrahedral morphology. Nitrogen sorption analysis indicates a highly porous material with a surface area exceeding 1400 m²  g^-1 . Furthermore, Fe-HHTP-MOF shows broadband absorption from 475 up to 1900 nm with excellent absorption capability of 98.5 % of the incoming light over the visible spectral region. Electrical conductivity measurements of pressed pellets reveal a high intrinsic electrical conductivity of up to 10^-3  S cm^-1 . Quantum mechanical calculations predict Fe-HHTP-MOF to be an efficient electron conductor, exhibiting continuous charge-carrier pathways throughout the structure.