Large Single Crystals Of Two-Dimensional Pi-Conjugated Metal- Organic Frameworks Via Biphasic Solution-Solid Growth

Two-dimensional (2D) pi-conjugated metal-organic frameworks (pi MOFs) are a new class of designer electronic materials that are porous and tunable through the constituent organic molecules and choice of metal ions. Unlike typical MOFs, 2D pi MOFs exhibit high conductivity mediated by delocalized pi-electrons and have promising applications in a range of electrical devices as well as exotic physical properties. Here, we develop a growth method that generates single-crystal plates with lateral dimensions exceeding 10 mu m, orders of magnitude bigger than previous methods. Synthesis of large single crystals eliminates a significant impediment to the fundamental characterization of the materials, allowing determination of the intrinsic conductivity and mobility along the 2D plane of pi MOFs. A representative 2D pi MOF, Ni-CAT-1, exhibits a conductivity of up to 2 S/cm, and Hall measurement reveals the origin of the high conductivity. Characterization of crystalline 2D pi MOFs creates the foundation for developing electronic applications of this promising and highly diverse class of materials.