Vlasceanu Alexandru, Koerstz Mads, Skov Anders B, Mikkelsen Kurt V, Nielsen Mogens Brøndsted
Department of Chemistry and Center for Exploitation of Solar Energy, University of Copenhagen, Universitetsparken 5, DK-2100, Copenhagen Ø, Denmark.
Angew Chem Int Ed Engl. 2018 May 22;57(21):6069-6072. doi: 10.1002/anie.201712942. Epub 2018 Apr 20.
Molecules comprised of three covalently linked bi-stable switches can exist in states described by a combination of binary numbers, one for each individual switch: ⟨000⟩, ⟨001⟩, etc. Here we have linked three photo-/thermoswitches together in a rigid macrocyclic structure, one azobenzene (bit no 1) and two dihydroazulenes (DHAs; bits no 2 and 3) and demonstrate how electronic interactions and unfavorable strain in some states can be used to control the speed by which a certain state is reached. More specifically, upon irradiation of state ⟨000⟩, the AZB isomerizes from trans to cis and the two DHAs to vinylheptafulvenes (VHFs), generating ⟨111⟩. The thermal VHF-to-DHA back-reactions from this state also occur stepwise and can be accelerated by photo-induced AZB cis-to-trans conversion, proceeding via ⟨011⟩ to ultimately furnish ⟨000⟩. Overall, the accessibility to a specific state of one bit was found to depend on the states of its neighboring bits.
由三个共价连接的双稳态开关组成的分子可以存在于由二进制数组合描述的状态中，每个单独的开关对应一个二进制数：⟨000⟩、⟨001⟩等。在这里，我们将三个光/热开关连接在一个刚性大环结构中，一个偶氮苯（位1）和两个二氢薁（DHA；位2和3），并展示了某些状态下的电子相互作用和不利应变如何用于控制达到特定状态的速度。更具体地说，在照射⟨000⟩状态时，偶氮苯从反式异构化为顺式，两个二氢薁异构化为乙烯基七富烯（VHF），生成⟨111⟩。从该状态开始的热VHF到DHA的逆向反应也逐步发生，并且可以通过光诱导的偶氮苯顺式到反式转化加速，经由⟨011⟩最终提供⟨000⟩。总体而言，发现一个位的特定状态的可达性取决于其相邻位的状态。
