Search

Abstract Polymer-based pure organic room-temperature phosphorescent materials have tremendous advantages in applications owing to their low cost, vast resources, and easy processability. However, designing polymer-based room-temperature phosphorescent materials with large Stokes shifts as key requirements in biocompatibility and environmental-friendly performance is still challenging. By generating charge transfer states as the gangplank from singlet excited states to triplet states in doped organic molecules, we find a host molecule (pyrrolidone) that affords charge transfer with doped guest molecules, and excellent polymer-based organic room-temperature phosphorescent materials can be easily fabricated when polymerizing the host molecule. By adding polyaromatic hydrocarbon molecules as electron-donor in polyvinylpyrrolidone, efficient intersystem crossing and tunable phosphorescent from green to near-infrared can be achieved, with maximum phosphorescence wavelength and lifetime up to 757 nm and 3850 ms, respectively. These doped polyvinylpyrrolidone materials have good photoactivation properties, recyclability, advanced data encryption, and anti-counterfeiting. This reported design strategy paves the way for the design of polyvinylpyrrolidone-based room-temperature phosphorescent materials.

Abstract In the presence of acetic acid as modulated agent, Keggin‐H3PW12O40 (K‐PW12) has been encapsulated into UIO‐66(Zr) by the solvothermal method. The as‐synthesized K‐PW12@UIO‐66(Zr) composite has further been characterized by PXRD, TG, FTIR, ICP‐AES, N2 isothermal adsorption, SEM and TEM. The results exhibit that Keggin‐H3PW12O40 is entrapped into the interior cage of UIO‐66(Zr) framework which is enlarged by losing terephthalic acid linker in the presence of acetic acid. K‐PW12@UIO‐66(Zr) composite can efficiently catalyse the esterification of methanol and oleic acid into biodiesel.

Construction of spirocyclic pyrrolidines bearing a spiro quaternary stereocenter is an enormous challenge in synthetic organic chemistry. In this report, we introduce a Ag(I)/CAAA-amidphos-catalyzed enantioselective 1,3-dipolar cycloaddition between azomethine ylides and α-methylene-γ-butyrolactone as an effective strategy for the construction of excellent endo-selective spiro-[butyrolactone-pyrrolidine] derivatives. Meanwhile, the catalytic system was also successfully applied in the three-component one-pot reaction of azomethine ylides formed in situ under the action of N,N′-diisopropylcarbodiimide serving as a dehydrator. Under the optimal conditions, endo-pyrrolidine derivatives bearing a spiro quaternary stereocenter were obtained with high to excellent yields (up to 95% yield) and enantioselectivities (up to 93% ee).

A metal-free one-pot cascade process involving reduction of nitroarenes, cyclization, and sequential hydrogenation of imines with B2cat2 and water was developed to construct dihydroquinoxalinones and tetrahydroquinoxalines directly from readily available 2-nitroanilines or o-dinitrobenzenes with α-ketoesters and a-diketones. This strategy provides various dihydroquinoxalinones and tetrahydroquinoxalines in good to excellent yields and tolerance to many functional groups. Mechanism studies by control experiments and density functional theory (DFT) calculations show that this cascade procedure involves the deoxygenative reduction of nitroarenes, the Maillard reaction, and hydrogenation to produce dihydroquinoxalinones and tetrahydroquinoxalines. This method aims to reduce the environmental impact while maintaining high yields and selectivity for both nitroarene reduction and the synthesis of dihydroquinoxalinones and tetrahydroquinoxalines. [ABSTRACT FROM AUTHOR]