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Multistate Photoswitches: Macrocyclic Dihydroazulene/Azobenzene Conjugates
Author(s) -
Vlasceanu Alexandru,
Koerstz Mads,
Skov Anders B.,
Mikkelsen Kurt V.,
Nielsen Mogens Brøndsted
Publication year - 2018
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201712942
Subject(s) - azobenzene , molecule , binary number , irradiation , covalent bond , molecular switch , state (computer science) , chemistry , materials science , photochemistry , chemical physics , physics , computer science , algorithm , arithmetic , mathematics , quantum mechanics , organic chemistry
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.