Electronic Challenges of Retrofitting 2D Electrically Conductive MOFs to Form 3D Conductive Lattices

Porous electrical conductors offer opportunities for next-generation energy storage solutions and electrocatalytic technologies. Metal–organic frameworks are one of the highest porosity scaffolds but typically feature low electrical conductivity due to their highly ionic metal–ligand interface. In this paper, we use computational approaches to study the inclusion of ligating pillars in a known electrically conductive framework, Ni3(hexaiminobenzene)2. We hypothesize that because Ni3(hexaiminobenzene)2 is an in-plane conductor, retrofitting this material may yield a 3D-connected network with metallicity in all crystallographic directions. However, we find that while this strategy likely yields unstable connectivity for the Ni2+ system, the use of either Cr2+ or Fe2+ provides a unique avenue to form 3D-connected conductors. The study further highlights the critical role of the metal dz2 orbitals in creating conductive metal–organic frameworks.