A composite material, {Fe(L)(TPPE)0.5⋅3 CH3OH}n, has been constructed by integrating the spin‐crossover (SCO) subunit ...FeII{diethyl(E,E)‐2,2′‐1,2‐phenyl‐bis(iminomethylidyne)bis(3‐oxobutanoate)‐(2‐)‐N,N′,O3,O3′} and the highly luminescent connector 1,1,2,2‐tetrakis(4‐(pyridin‐4‐yl)phenyl)‐ethene. Its structure contains four staggered 4×4 layers and intercalated methanol. The packing is dominated by considerable H‐bonds either between adjacent layers and between layers and guests. A crystal‐structure transformation was detected upon removal of the guest molecules. The SCO transition of the solvated crystals is centered at ca. 215 K with a non‐symmetrical hysteresis of 25 K wide, and the desolvated Fe(L)(TPPE)0.5n exhibits gradual SCO without hysteresis. Intriguingly, the intensity of the fluorescence at 460 nm for the latter is maximized at the SCO transition. The energy transfer between luminescent and SCO entities is achievable as confirmed by theoretical calculations.
A square‐grid layered FeII coordination polymer based on a luminophore connector TPPE was studied. This framework not only features a solvent‐dependent structure and spin crossover (SCO) behavior, but also exhibits a switch between spin transition and fluorescence for the guest‐free species. Theoretical calculation reveals an energy‐transfer mechanism.
Metal-organic frameworks (MOFs) that respond to external stimuli such as guest molecules, temperature, or redox conditions are highly desirable. Herein, we coupled redox-switchable properties with ...breathing behavior induced by guest molecules in a single framework. Guided by topology, two flexible isomeric MOFs, compounds 1 and 2, with a formula of In(Me
NH
)(TTFTB), were constructed via a combination of In(COO)
metal nodes and tetratopic tetrathiafulvalene-based linkers (TTFTB). The two compounds show different breathing behaviors upon the introduction of N
. Single-crystal X-ray diffraction, accompanied by molecular simulations, reveals that the breathing mechanism of 1 involves the bending of metal-ligand bonds and the sliding of interpenetrated frameworks, while 2 undergoes simple distortion of linkers. Reversible oxidation and reduction of TTF moieties changes the linker flexibility, which in turn switches the breathing behavior of 2. The redox-switchable breathing behavior can potentially be applied to the design of stimuli-responsive MOFs.
Developing highly efficient and cost‐effective electrocatalysts to boost the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is vital for the sustainable energy systems. The ...nitrogen and phosphorus codoped vesica‐like carbons with hierarchical nanoporous structure are synthesized through an efficient self‐polymerization strategy with the template of g‐C3N4 monolith. Featuring sufficient heteroatom‐doping, well‐developed porous hierarchy, and high electrochemical surface area, the fabricated carbon materials exhibit considerable activity and robust stability in both electrocatalyzing ORR and OER, in competition with the precious metal electrocatalysts, which are thus capable of using as air cathode catalysts for rechargeable Zn‐air batteries, affording large discharge current density and impressive operation stability.
Get on top of your electrocat: Hierarchically porous heteroatoms‐doped vesica‐like carbons were synthesized through a polymerization‐carbonization approach using g‐C3N4 as template, exhibiting considerable performance towards ORR and OER.
Herein, we report a cobalt‐catalyzed hydroarylation of maleimides followed by an annulation sequence for the synthesis of polycyclic azaheterocycles in one pot. The reaction proceeds under ...redox‐neutral conditions and is compatible with various functional groups. Notably, the as‐prepared product exhibits potential photophysical properties.
A major challenge is the development of multifunctional metal–organic frameworks (MOFs), wherein magnetic and electronic functionality can be controlled simultaneously. Herein, we rationally ...construct two 3D MOFs by introducing the redox active ligand tetra(4‐pyridyl)tetrathiafulvalene (TTF(py)4) and spin‐crossover FeII centers. The materials exhibit redox activity, in addition to thermally and photo‐induced spin crossover (SCO). A crystal‐to‐crystal transformation induced by I2 doping has also been observed and the resulting intercalated structure determined. The conductivity could be significantly enhanced (up to 3 orders of magnitude) by modulating the electronic state of the framework via oxidative doping; SCO behavior was also modified and the photo‐magnetic behavior was switched off. This work provides a new strategy to tune the spin state and conductivity of framework materials through guest‐induced redox‐state switching.
A 3D FeII metal–organic framework (MOF) based on the tetrathiafulvalene tetrapyridyl ligand and its I2‐doped analogue were prepared. The TTF moieties provide redox activity, and I2 doping improves the conductive properties. Doping or light irradiation significantly alters the magnetic properties, indicating the material has electronically and photo‐switchable spin‐crossover properties.
Bread wheat expanded its habitat from a core area of the Fertile Crescent to global environments within ~10,000 years. The genetic mechanisms of this remarkable evolutionary success are not well ...understood. By whole-genome sequencing of populations from 25 subspecies within the genera Triticum and Aegilops, we identified composite introgression from wild populations contributing to a substantial portion (4-32%) of the bread wheat genome, which increased the genetic diversity of bread wheat and allowed its divergent adaptation. Meanwhile, convergent adaptation to human selection showed 2- to 16-fold enrichment relative to random expectation-a certain set of genes were repeatedly selected in Triticum species despite their drastic differences in ploidy levels and growing zones, indicating the important role of evolutionary constraints in shaping the adaptive landscape of bread wheat. These results showed the genetic necessities of wheat as a global crop and provided new perspectives on transferring adaptive success across species for crop improvement.
Organic ultralong room‐temperature phosphorescence (RTP) materials have attracted great attention for their wide applications in optoelectronic devices and bioimaging. However, the development of ...these materials remains a challenging task, partially due to the lack of rational molecular design strategies and unclear luminescence mechanisms. Herein, we present a method for facile access to structurally diverse substituted 1‐aminoisoquinoline derivatives through a copper‐catalyzed one‐pot three‐component coupling reaction that provides a promising approach to rapidly assemble a library of 1‐aminoisoquinolines for exploring the regularity of the host‐guest doped system. A series of host‐guest RTP materials with wide‐ranging lifetimes from 4.4 to 299.3 ms were constructed by doping various substituted isoquinolines derivatives into benzophenone (BP). Furthermore, 4 r/BP nanoparticles could be used for in‐vivo imaging with a signal‐to‐noise ratio value as high as 32, revealing the potential of the isoquinoline framework for the construction of high‐performance RTP materials.
A convenient, efficient and direct approach toward structurally diverse substituted 1‐aminoisoquinoline derivatives has been developed. By simply doping the 1‐aminoisoquinolines into benzophenone (BP), a series of RTP systems with tunable lifetime luminescence can be realized. 4 r/BP nanoparticles could be used for in‐vivo imaging with a high signal‐to‐noise ratio.
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