Chen Lei, De Bo Guillaume
Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom.
J Am Chem Soc. 2024 Jun 7;146(24):16381-4. doi: 10.1021/jacs.4c05168.
Mechanophores (mechanosensitive molecules) are usually activated by pulling them with covalently attached polymers. A rotaxane actuator offers a new geometry of activation as the macrocycle pushes against a stoppering mechanophore. Here we compare both and activations and show that pushing is more efficient and selective than pulling. We found that the pulling activation of a bulky furan/maleimide adduct occurs via two competing dissociation pathways: retrocycloaddition and heterolytic cleavage (generating a trityl cation in the process), while the same adduct only cleaves by retrocycloaddition during pushing activation. These results further demonstrate the efficacy and versatility of rotaxane actuators.
机械力发色团（机械敏感分子）通常通过用共价连接的聚合物拉动它们来激活。轮烷致动器提供了一种新的激活几何结构，因为大环推压一个封端的机械力发色团。在这里，我们比较了拉动和推压两种激活方式，并表明推压比拉动更有效且更具选择性。我们发现，一个庞大的呋喃/马来酰亚胺加合物的拉动激活通过两条相互竞争的解离途径发生：逆环加成和异裂（在此过程中产生一个三苯甲基阳离子），而相同的加合物在推压激活过程中仅通过逆环加成裂解。这些结果进一步证明了轮烷致动器的有效性和多功能性。
