Su Jessica K, Feist John D, Yang Jinghui, Mercer Jaron A M, Romaniuk Joseph A H, Chen Zhixing, Cegelski Lynette, Burns Noah Z, Xia Yan
Department of Chemistry , Stanford University , Stanford , California 94305 , United States.
J Am Chem Soc. 2018 Oct 3;140(39):12388-12391. doi: 10.1021/jacs.8b08908. Epub 2018 Sep 20.
We have recently reported a polymechanophore system, polyladderene (PLDE), which dramatically transforms into polyacetylene (PA) upon mechanical stimulation. Herein, we optimized conditions to synthesize unprecedented block copolymers (BCPs) containing a force-responsive block by sequential ring-opening metathesis polymerization of different norbornenes and bromoladderene. Successful extension from PLDE to other blocks required careful timing and low temperatures to preserve the reactivity of the PLDE-appended catalyst. The PLDE-containing BCPs were sonochemically activated into visually soluble PA with a maximum absorption λ ≥ 600 nm and unique absorption patterns corresponding to noncontinuous activation of ladderene units. Access to polymechanophore BCPs paves the way for new stress-responsive materials with solution and solid state self-assembly behaviors and incorporation of polymechanophores into other materials.
我们最近报道了一种多机械响应基团体系——聚梯烯（PLDE），它在机械刺激下会显著转变为聚乙炔（PA）。在此，我们通过对不同降冰片烯和溴代梯烯进行顺序开环易位聚合，优化了合成含力响应嵌段的前所未有的嵌段共聚物（BCP）的条件。从PLDE成功扩展到其他嵌段需要精确的时间控制和低温，以保持PLDE连接的催化剂的活性。含PLDE的BCP通过声化学活化转变为在视觉上可溶的PA，其最大吸收波长λ≥600 nm，且具有与梯烯单元的非连续活化相对应的独特吸收模式。获得聚机械响应基团BCP为具有溶液和固态自组装行为的新型应力响应材料以及将聚机械响应基团引入其他材料铺平了道路。
