Photo Responsive Electron and Proton Conductivity within a Hydrogen‐Bonded Organic Framework

Abstract Rational design of crystalline porous materials with coupled proton‐electron transfer has not yet been reported to date. Herein, we report a donor‐acceptor (D‐A) π‐π stacking hydrogen‐bonded organic framework (HOF; HOF‐FJU‐36 ) with zwitterionic 1,1′‐bis(3‐carboxybenzyl)‐4,4′‐bipyridinium (H 2 L 2+ ) as acceptor and 2,7‐naphthalene disulfonate (NDS 2− ) as donor to form a two‐dimensional (2D) layer. Three water molecules were situated in the channels to connect with acidic species through hydrogen bonding interactions to give a 3D framework. The continuous π‐π interactions along the a axis and the smooth H‐bonding chain along the b axis provide the electron and proton transfer pathways, respectively. After 405 nm light irradiation, the photogenerated radicals could simultaneously endow HOF‐FJU‐36 with photoswitchable electron and proton conductivity due to coupled electron‐proton transfer. By single‐crystal X‐ray diffraction (SCXRD) analyses, X‐ray photoelectron spectroscopy (XPS), transient absorption spectra and density functional theory (DFT) calculations, the mechanism of the switchable conductivity upon irradiation has been demonstrated.