386 research outputs found
Dual-ion charge-discharge behaviors of Na-NiNc and NiNc-NiNc batteries
Dual-ion sodium-organic secondary batteries were produced with anti-aromatic porphyrinoid, NiNc, as an active electrode material, which exhibited inherent charge-discharge behavior with high discharge capacity, high stability, and high Coulombic efficiency at high current density (132.6 mA h g⁻¹ discharge capacity and 99.4% efficiency at the 100th cycle with 1 A g⁻¹ of current density and 95.3 mA h g⁻¹ discharge capacity and 99.3% efficiency at the 100th cycle with 2 A g⁻¹ of current density)
Stacked Antiaromatic Porphyrins
Aromaticity is a key concept in organic chemistry. Even though this concept has already been theoretically extrapolated to three dimensions, it usually still remains restricted to planar molecules in organic chemistry textbooks. Stacking of antiaromatic π-systems has been proposed to induce three-dimensional aromaticity as a result of strong frontier orbital interactions. However, experimental evidence to support this prediction still remains elusive so far. Here we report that close stacking of antiaromatic porphyrins diminishes their inherent antiaromaticity in the solid state as well as in solution. The antiaromatic stacking furthermore allows a delocalization of the π-electrons, which enhances the two-photon absorption cross-section values of the antiaromatic porphyrins. This feature enables the dynamic switching of the non-linear optical properties by controlling the arrangement of antiaromatic π-systems on the basis of intermolecular orbital interactions
Three-dimensional aromaticity in an antiaromatic cyclophane
Understanding of interactions among molecules is essential to elucidate the binding of pharmaceuticals on receptors, the mechanism of protein folding and self-assembling of organic molecules. While interactions between two aromatic molecules have been examined extensively, little is known about the interactions between two antiaromatic molecules. Theoretical investigations have predicted that antiaromatic molecules should be stabilized when they stack with each other by attractive intermolecular interactions. Here, we report the synthesis of a cyclophane, in which two antiaromatic porphyrin moieties adopt a stacked face-to-face geometry with a distance shorter than the sum of the van der Waals radii of the atoms involved. The aromaticity in this cyclophane has been examined experimentally and theoretically. This cyclophane exhibits three-dimensional spatial current channels between the two subunits, which corroborates the existence of attractive interactions between two antiaromatic π-systems
La fundación de la Madrasa al-Adāb por la Asociación de ulemas musulmanes argelinos en la ciudad de Hennaya (Tremecén) en 1950
A biphenyl-fused BODIPY was synthesized through a facile oxidative cyclization of peripheral aryl-substituents at the β-position of the BODIPY unit. The extended π-system of the fused BODIPY induces near-infrared (NIR) absorption and strong π–π interactions in the solid state. These features are beneficial for the application of the dye as a functional material. The biphenyl-fused BODIPY dye was demonstrated to exhibit photocurrent conversion ability on the basis of its <i>n</i>-type semiconducting property
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