Synthesis of Boron(III)‐Coordinated Subchlorophins and Their Peripheral Modifications

A pyrrole‐cleaving modification to transform boron(III) meso ‐triphenylsubporphyrin into boron(III) meso ‐triphenylsubchlorophin has been developed. Boron(III) subchlorophins thus synthesized show absorption and fluorescence spectra that are roughly similar to those of boron(III) subchlorins, but B ‐methoxy boron(III) subchlorophin showed considerably intensified fluorescence and a small Stokes shift. Peripheral modification reactions of B ‐phenyl boron(III) subchlorophin such as regioselective nitration with Cu(NO₃)₂⋅3 H₂O, ipso ‐substitution reactions of boron(III) α‐nitrosubchlorophin with CsF and CsCl, and Pd‐catalyzed cross‐coupling reactions of boron(III) α‐chlorosubchlorophin with arylacetylenes, have been also explored to tune the optical properties of subchlorophins.     

Porphyrin Antennas on Carbon Nanodots: Excited State Energy and Electron Transduction

We report the synthesis and electron donor–acceptor features of a novel nanohybrid, in which the light‐harvesting and electron‐donating properties of a meso ‐tetraarylporphyrin (TArP) are combined with the electron‐accepting features of nitrogen‐doped carbon nanodots (NCNDs). In particular, in an ultrafast process (>10¹² s⁻¹), visible‐light excitation transforms the strongly quenched porphyrin singlet excited states into short‐lived (225 ps) charge‐separated states. On the other hand, ultraviolet light excitation triggers a non‐resolvable transduction of singlet excited state energy from the NCNDs to the porphyrins, followed by the same charge separation observed upon visible light excitation.     

Stabilizing Liquids Using Interfacial Supramolecular Polymerization

The strong electrostatic interactions at the oil–water interface between a small molecule, 5,10,15,20‐tetrakis(4‐sulfonatophenyl)porphyrin, H₆TPPS, dissolved in water, and an amine terminated hydrophobic polymer dissolved in oil are shown to produce a supramolecular polymer surfactant (SPS) of H₆TPPS at the interface with a binding energy that is sufficiently strong to allow an intermolecular aggregation of the supramolecular polymers. SPSs at the oil–water interface are confirmed by in situ real‐space atomic force microcopy imaging. The assemblies of these aggregates can jam at the interface, opening a novel route to kinetically trap the liquids in non‐equilibrium shapes. The elastic film, comprised of SPSs, wrinkles upon compression, providing a strategy to stabilize liquids in non‐equilibrium shapes.     

Synthesis of C−C Bonded Two‐Dimensional Conjugated Covalent Organic Framework Films by Suzuki Polymerization on a Liquid–Liquid Interface

Synthesis of free‐standing two‐dimensional (2D) conjugated covalent organic framework (COF) films linked by C?C bonds is highly desirable. Now a very simple and mild strategy has been developed to synthesize them by Suzuki polymerization on a water–toluene interface in a refrigerator. The versatility of this strategy was confirmed by the successful synthesis of two different 2D‐COF films: a porous graphene and a porphyrin‐contained 2D‐COF. Both 2D‐COF films have large lateral size and their crystalline domains were visualized by high resolution TEM. Based on the wide compatibility of Suzuki reaction, our breakthrough work opened a door for the synthesis of various 2D conjugated COF films. For application studies, the porous graphene exhibits a good carrier mobility, which is much higher than ?C=N? linked 2D COF films and a good catalytic activity for hydrogen evolution reaction, which is comparable with nitrogen‐ or phosphorus‐doped graphene.     

Synthesis,Structures, and Near‐IR Absorption of Heterole‐Fused Earring Porphyrins

A reaction sequence of regioselective peripheral bromination, Suzuki–Miyaura coupling with 2‐borylated thiophene or pyrrole, and oxidative ring‐closure with FeCl₃ allowed the synthesis of heterole‐fused earring porphyrins 4Pd and 9Pd from the parent earring porphyrin 1 . Differently pyrrole‐fused porphyrins 5H and 6H and their Pd^II complexes 5Pd and 6Pd were also synthesized. The structures of 4Pd , 5H, 6Pd , and 8Pd have been revealed by X‐ray analysis to be slightly twisted owing to constraints imposed by heterole‐fused structures. 5Pd exhibits an intensified band at 1505 nm, while 4Pd and 9Pd display small but remarkably red‐shifted absorption bands reaching around 2200 nm.     

Heat-Treated Aerogel as a Catalyst for the Oxygen Reduction Reaction

Aerogels are fascinating materials that can be used for a wide range of applications, one of which is electrocatalysis of the important oxygen reduction reaction. In their inorganic form, aerogels can have ultrahigh catalytic site density, high surface area, and tunable physical properties and chemical structures—important features in heterogeneous catalysis. Herein, we report on the synthesis and electrocatalytic properties of an iron–porphyrin aerogel. 5,10,15,20-(Tetra-4-aminophenyl)porphyrin (H₂TAPP) and Fe^II were used as building blocks of the aerogel, which was later heat-treated at 600 °C to enhance electronic conductivity and catalytic activity, while preserving its macrostructure. The resulting material has a very high concentration of atomically dispersed catalytic sites (9.7×10²⁰ sites g⁻¹) capable of catalyzing the oxygen reduction reaction in alkaline solution (E_onset=0.92 V vs. RHE, TOF=0.25 e⁻ site⁻¹ s⁻¹ at 0.80 V vs. RHE).