Enhancing Electronic Conductivity and Solvent Accessible Porosity via Oxidative Deinsertion in a Vanadium Catecholate Framework
Koley, N; Walden, M. E.; Mollick, S. S.; Li, D.; Celio, H.; Carsch, K. M.; Aubrey, M. L.
J. Am. Chem. Soc. 2026, Submitted.
Three-dimensional metal–organic frameworks (MOFs) that combine high electronic conductivity with porosity remain rare because the structural features that promote charge transport often compromise porosity. Here, we report a redox-active three-dimensional vanadium catecholate framework, [(CH3)2NH2]2.5V(HOTP) (HOTP6– = 2,3,6,7,10,11-hexaoxidotriphenylene), an anionic MOF that is charge-balanced with [(CH3)2NH2]+ occupying the pores. Controlled topotactic oxidation using thianthrenium hexafluorophosphate enables the stepwise deinsertion of these charge-balancing cations, yielding five distinct oxidized phases. Spectroscopic analyses reveal that both the vanadium centers and HOTP linkers participate in the oxidation process, generating mixed-valence structures with Robin–Day class II/III delocalization across both metal and ligand components. Progressive oxidation and cation removal produce a dramatic enhancement in charge transport, culminating in an increase in electronic conductivity of nearly five orders of magnitude from ~10–6 S cm–1 in the unoxidized phase to 0.4(2) S cm–1 in the most oxidized phase, accompanied by near- complete removal of the cation from the pores. These results are a rare example of a porous framework in which electronic conductivity increases concomitantly with pore-vacating cation deinsertion, providing a strategy for reconciling electronic conductivity and pore accessibility in MOFs.