On the tendency of 1,2,3,6-tetrahydrobenzocyclobutene-3,6-diones for undergoing site-selective Diels-Alder reactions at the internal double bond
作者:Daniel F. Rothenfluh、Donald C. Craig、Michael N. Paddon-Row
DOI:10.1016/0040-4039(94)02413-6
日期:1995.2
Diels-Alderreactions of cyclobutene-3,6-diones, 5 and 6 with dienes 7 – 10 gave predominantly adducts arising from attack of the diene at the internaldoublebond of the diones. Ab initio MO calculations suggest that the observed site selectivity of cyclobutene-3,6-diones is due to strain effects rather that to frontier orbital effects.
Benzoquinone‐ and Naphthoquinone‐Bearing Polymers Synthesized by Ring‐Opening Metathesis Polymerization as Cathode Materials for Lithium‐Ion Batteries
作者:Yeqing Shi、Pengfei Sun、Jixing Yang、Yunhua Xu
DOI:10.1002/cssc.201902966
日期:2020.1.19
AbstractOrganic electrode materials have attracted great interest for next‐generation lithium‐ion batteries owing to their merits of low cost, resource sustainability, and environmental friendliness. Dissolution in organic electrolyte is one of critical factors that limit their development, and constructing corresponding polymers is an effective way to prevent it. Herein, the synthesis of benzoquinone‐ and naphthoquinone‐bearing polymers by ring‐opening metathesis polymerization of monomers with an exo‐type four‐membered ring between polymerizable norbornene and redox‐active quinone units is reported. They exhibit significantly reduced solubility and clearly enhanced electrochemical performance. In particular, a high capacity (189.7 mAh g−1 at 0.1 C, 1 C=216.1 mA g−1), stable cycling (75.6 % capacity retention after 500 cycles at 2 C), and good rate capability (retaining 80.4 % from 0.1 to 2 C) were obtained for the naphthoquinone‐bearing polymer, which stand out among naphthoquinone‐bearing polymer electrode materials. This work offers rational molecular design and a new polymerization strategy to construct high‐performance polymer electrode materials.