Transferring the solution-state chemistry of organic-based molecular switches (OMS) into the solid state usually faces several fatal problems, such as spatial confinement or inefficient conversion. As a result, their switching behavior usually cannot be maintained. Herein, we report a redoxswitchable metal−organic framework (MOF) that can undergo a reversible single-crystal-to-single-crystal (SCSC) transformation through a hydroquinone/quinone redox reaction. The redox-triggered transformation is quantitatively reversible while maintaining the crystallinity of the MOF scaffold. In addition, the transformation occurs gradually in the MOF backbone and from the outsurface of MOF to the inside. This study represents a general strategy to enable efficient conversion of the functionality of an OMS from solution into solid state, by incorporation of OMS into the framework of MOF. Furthermore, the material exhibits interesting changes in spectroscopic properties through reversible SCSC transformation and, thus, may be a starting point for the use of such materials in memory storage or redox-based electronic devices.

NaCl-assisted pyrolysis of an Fe porphyrinic coordination network combined with concentrated-sulfuric-acid post-activation results in a hierarchically porous Fe–N–C nanospindle catalyst.

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Gaseous Raman lasers cover a range of wavelengths but lack wavelength tunability. Here, a 1 c m − 1 linewidth 532 nm laser was used as a pump laser, and with a narrow-linewidth seed laser injection, a narrow-linewidth first Stokes (S1) Raman laser was achieved. By tuning the wavelength of the seed laser, a tuning range of S1 up to 1 c m − 1 was obtained. The wavelengths of the first anti-Stokes and second Stokes lasers could also be tuned. A theoretical model was developed, and spectral profiles of Raman lasers from experiments and simulations agreed well; further simulation predicted that the linewidth of S1 could be compressed to as narrow as 0.01 c m − 1 under optimal conditions. A universal method of fine-tunable Raman lasers is presented that can be utilized in several important applications.