Palladium-Catalyzed Double Carbonylative Cyclization of Benzoins: Synthesis and Photoluminescence of Bis-Ester-Bridged Stilbenes

Carbonyl-Based Redox-Active Compounds as Organic Electrodes for Batteries: Escape from Middle-High Redox Potentials and Further Improvement?

Extracting─from the vast space of organic compounds─the best electrode candidates for achieving energy material breakthrough requires the identification of the microscopic causes and origins of various macroscopic features, including notably electrochemical and conduction properties. As a first guess of their capabilities, molecular DFT calculations and quantum theory of atoms in molecules (QTAIM)-derived indicators were applied to explore the family of pyrano[3,2-b]pyran-2,6-dione (PPD, i.e., A0) compounds, expanded to A0 fused with various kinds of rings (benzene, fluorinated benzene, thiophene, and merged thiophene/benzene). A glimpse of up-to-now elusive key incidences of introducing oxygen in vicinity to the carbonyl redox center within 6MRs─as embedded in the A0 core central unit common to all A-type compounds─has been gained. Furthermore, the main driving force toward achieving modulated low redox potential/band gaps thanks to fusing the aromatic rings for the A compound series was discovered.

Synthesis of tetracyclic 4H-benzo[5,6]chromeno[3,4-d]oxazoles via palladium-catalyzed intramolecular direct heteroarylation

We report a palladium-catalyzed intramolecular direct heteroarylation of oxazole tethered β-naphthols to access corresponding tetracyclic 4H-benzo[5,6]chromeno[3,4-d]oxazoles. Various functional groups are well tolerated and furnished the desired products in good to excellent yields under the present reaction conditions. The scale-up reaction and synthetic utility of the resulting molecules have been demonstrated. Moreover, UV/vis absorption and fluorescence emission properties have been evaluated for these polyheterocyclic compounds.

Overview of coumarin-fused-coumarins: synthesis, photophysical properties and their applications

Coumarin-fused-coumarins have attracted significant attention in the scientific world owing to their boundless applications in interdisciplinary areas. Various synthetic pathways have been developed to construct novel coumarin-fused-coumarin analogues by the fusion of modern methodologies with a classical Pechmann reaction or Knoevenagel condensation. Owing to their extended molecular framework, they possess interesting photophysical properties depending on the fused coumarin ring systems. This review highlights previously published reports on the synthetic strategies for structurally diverse coumarin-fused-coumarins. Furthermore, the scope of the synthesized biscoumarin-fused entities is described by highlighting their photophysical properties and applications.

Mechanoresponsive turn-on phosphorescence by a desymmetrization approach

The room-temperature phosphorescence (RTP) of metal-free organic crystals is normally quenched by mechanical stimulation. Herein, we demonstrate the opposite mechanoresponse of turn-on RTP. A desymmetrization of a C₂-symmetric 1,2-diketone creates space for molecular motion in the crystal, quenching the RTP from the crystal while maintaining that from the amorphous solid.

Thioarylmaleimides: accessible, tunable, and strongly emissive building blocks

A series of thioarylmaleimides was synthesized to investigate how variation of the thioaryl group can be used to control absorption and emission properties in solution and in the solid-state. Fine-tuning of the photochemical properties was found to be possible using this strategy, and a rainbow of colours and emission wavelengths are accessible in a single step from commercially available compounds.