Acid-Dependent Charge Transport in a Solution-Processed 2D Conductive Metal-Organic Framework

The development of conductive metal-organic frameworks (MOFs) presents a unique challenge in materials chemistry because it is unclear how to dope them. Here, we demonstrate that the inclusion of pendant amines on hexahydroxytriphenylene linkages results in two-dimensional (2D) polycrystalline frameworks Cu₃(HHTATP)₂, isostructural to its Cu₃(HHTP)₂ parent, and exhibits the highest electrical conductivity of 1.21 S/cm among 2D MOFs featuring CuO₄ metal nodes. Moreover, the bulk material can be treated with acid, resulting in a protonation-dependent increase in the conductivity. By spin-coating the acidic solution, we fabricated large-area thin films and collectively demonstrated an intuitive route to solution-processable, dopable, conductive MOFs.