Merging One‐ and Multi‐Photon Processes in Hydrogen‐Bonded Organic Frameworks for Enhanced NIR Light‐Driven Photothermal and Photochemical Conversions

Abstract Direct application of near‐infrared (NIR) light for solar‐thermal and solar‐chemical conversions is of emergent interest to improving efficiency in solar‐energy utilization. Herein, we report a synthetic approach to NIR‐responsive materials by self‐assembly of hydrogen‐bonded organic frameworks ( HOF‐1/2/3 ) from multifunctionalized Ru‐components incorporating chiral, photoactive, H‐bonding, π‐stacking, and protonation/deprotonation subunits. Significantly, protonation of the imidazole‐subunits in HOF‐3 promotes densified packing to extend NIR absorption tail up to 1100 nm with a narrowed bandgap of 1.41 eV, meanwhile leads to spontaneous resolution of enantiomeric Δ‐/Λ‐HOF‐3 . Consequently, remarkably enhanced photothermal effect and photocatalytic performance, including chiroptical activity induced by circularly polarized NIR light, are achieved through synergy of direct one‐ and multi‐photon NIR absorption, underscoring effectiveness to bring multifunctionalities into ordered HOFs for generation of robust and effective materials with multimode NIR responsiveness.