Switchable Anisotropic/Isotropic Photon Transport in a Double‐Dipole Metal–Organic Framework via Radical‐Controlled Energy Transfer

Abstract Directional control of photon transport at micro/nanoscale holds great potential in developing multifunctional optoelectronic devices. Here, the switchable anisotropic/isotropic photon transport is reported in a double‐dipole metal–organic framework (MOF) based on radical‐controlled energy transfer. Double‐dipole MOF microcrystals with transition dipole moments perpendicular to each other have been achieved by the pillared‐layer coordination strategy. The energy transfer between the double dipolar chromophores can be modulated by the photogenerated radicals, which permits the in situ switchable output on both polarization (isotropy/anisotropy state) and wavelength information (blue/red‐color emission). On this basis, the original MOF microcrystal with isotropic polarization state displays the isotropic photon transport and similar reabsorption losses at various directions, while the radical‐affected MOF microcrystal with anisotropic polarization state shows the anisotropic photon transport with distinct reabsorption losses at different directions, finally leading to the in situ switchable anisotropic/isotropic photon transport. These results offer a novel strategy for the development of MOF‐based photonic devices with tunable anisotropic performance.