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, Ni-3(hexaiminobenzene)(2). We hypothesize that because Ni-3(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 d(z)(2) orbitals in creating conductive metal-organic frameworks.
Abstract