Unusual 3,4-Oxidative Coupling Polymerization on 1,2,5-Trisubstituted Pyrroles for Novel Porous Organic Polymers

Porous organic polymers (POPs) have demonstrated promising task-specific applications due to their structure designability and thus functionality. Herein, an unusual 3,4-polymerization on 1,2,5-trisubstituted pyrroles has been developed to give linear polypyrrole-3,4 in high efficiency, with Mn of 20000 and PDI of 1.7. This novel polymerization technique was applied to prepare a series of polypyrrole-based POPs (PY-POP-1–4), which exhibited high BET surface areas (up to 762 m2 g–1) with a meso–micro–supermicro hierarchically porous structure. Furthermore, PY-POPs were doped in the mixed matrix membranes based on the polysulfone matrix to enhance the gas permeability and gas pair selectivity, with H2/N2 selectivity up to 84.6 and CO2/CH4 and CO2/N2 selectivity up to 46.8 and 39.6

Incorporation of Azo-Linkage to Elevate the Redox Potential of Triphenylamine-Based Porous Organic Polymer Cathodes for Li-Ion Batteries

Porous organic polymers with triphenylamine (TPA) subunits have attracted a lot of attention as advanced electrodes for Li-ion batteries (LIBs) but with poor rate performance and low stability. In this work, azo-linkage has been incorporated into TPA-based porous organic polymers to increase the redox potential while maintaining the capacity of TPA. The cathodes based on azo-linked porous organic polymers (Azo-POP-10, Azo-POP-11, and Azo-POP-12) exhibited a high redox potential of 3.8 V and can be charged up to 4.5 V. A stable electrochemical performance is observed and our designed cathodes retain 84% (Azo-POP-10), 87% (Azo-POP-11), and 75% (Azo-POP-12) of their initial capacities at a current density of 1000 mAg–1. Over 60% capacity retention is observed even after 1000 charge–discharge cycles. Moreover, the cathodes still delivered a stable capacity even at a very high current density of 20,000 mAg–1, showing excellent stability under fast charging conditions. A cutoff potential of 4.5 V and a current density of 20,000 mAg–1 are the highest parameters for TPA-based materials to date. The unique material design is mainly responsible for this excellent performance, and we believe that this report can inspire the further development of organic cathodes with fast charging and better stability

Exothermic or Endothermic Decomposition of Disubstituted Tetrazoles Tuned by Substitution Fashion and Substituents

Nitrogen-rich compounds such as tetrazoles are widely used as candidates in gas-generating agents. However, the details of the differentiation of the two isomers of disubstituted tetrazoles are rarely studied, which is very important information for designing advanced materials based on tetrazoles. In this article, pairs of 2,5- and 1,5-disubstituted tetrazoles were carefully designed and prepared for study on their thermal decomposition behavior. Also, the substitution fashion of 2,5- and 1,5- and the substituents at C-5 position were found to affect the endothermic or exothermic properties. This is for the first time to the best of our knowledge that the thermal decomposition properties of different tetrazoles could be tuned by substitution ways and substitute groups, which could be used as a useful platform to design advanced materials for temperature-dependent rockets. The aza-Claisen rearrangement was proposed to understand the endothermic decomposition behavior

A crystalline bisindolylmaleimide with strong solid-state fluorescence of red color and its analogous cross-linked polymer without fluorescence

<p>A crystalline bisindolylmaleimide (BIM) <b>3</b> with strong fluorescence in the solid state was prepared and studied. Its analogous cross-linked polymer <b>4</b> with the same BIMs fluorophore was designed and characterized. The investigation of the covalent bonding networking effect on the solid-state fluorescence was carried out by the comparison between <b>3</b> and <b>4</b>.</p