The incorporation of mechanophores,motifs that transform mechanical stimulus into chemical reaction or optical variation,allows creating materials with stressresponsive properties.The most widely used mechanophore gen...The incorporation of mechanophores,motifs that transform mechanical stimulus into chemical reaction or optical variation,allows creating materials with stressresponsive properties.The most widely used mechanophore generally features a weak bond,but its cleavage is typical an irreversible process.Here,we showed that this problem can be solved by folding–unfolding of a molecular tweezer.We systematically studied the mechanochromic properties of polyurethanes with cyano-substituted oligo(p-phenylene)vinylene(COP)tweezer(DPU).As a control experiment,a class of polyurethanes containing only a single COP moiety(MPU)was also prepared.The DPU showed prominent mechanochromic properties,due to the intramolecular folding–unfolding of COP tweezer under mechanical stimulus.The process was efficient,reversible and optical detectable.However,due to the disability to form either intramolecular folding or intermolecular aggregation,the MPU sample was mechanical inert.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Grant Nos.52103141 and 51803090)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20181025 and BK20191022)for financial support.
文摘The incorporation of mechanophores,motifs that transform mechanical stimulus into chemical reaction or optical variation,allows creating materials with stressresponsive properties.The most widely used mechanophore generally features a weak bond,but its cleavage is typical an irreversible process.Here,we showed that this problem can be solved by folding–unfolding of a molecular tweezer.We systematically studied the mechanochromic properties of polyurethanes with cyano-substituted oligo(p-phenylene)vinylene(COP)tweezer(DPU).As a control experiment,a class of polyurethanes containing only a single COP moiety(MPU)was also prepared.The DPU showed prominent mechanochromic properties,due to the intramolecular folding–unfolding of COP tweezer under mechanical stimulus.The process was efficient,reversible and optical detectable.However,due to the disability to form either intramolecular folding or intermolecular aggregation,the MPU sample was mechanical inert.
