Department of Chemistry Seminar - Superconductors and 3D Graphenes: Wild Dreams of Metal-Organic Frameworks

Speaker: Professor Zhengtao XU

Institution: Institute of Materials Research and Engineering (IMRE), A*STAR, Singapore

Hosted By: Professor Yangjian QUAN

Abstract

In the first part, we employ a two-step strategy for accessing crystalline porous covalent networks of highly conjugated π-electron systems emulating the coveted 3D graphenes (Figure, left, a). For this, we first assembled a crystalline metal-organic framework (MOF) precursor based on Zr(IV) ions and a linear dicarboxyl linker molecule featuring backfolded, highly unsaturated alkyne backbones; massive thermocyclization of the organic linkers was then triggered to install highly conjugated, fused-aromatic bridges throughout the MOF scaffold while preserving the crystalline order. The resultant polycyclic aromatic network exhibits greatly enhanced stability, electroactivity and charge transport. In the second part, we report breakthrough in the modular synthesis of MOF solids extensively equipped with the mercaptan function, in order to fully exploit the unique metal-uptake, catalytic and electronic properties afforded by the thiol function, e.g., potential superconductivity observed of a designer coordination polymer system sporting the chemically soft mercaptan and hard carboxyl groups.