Vegge Siri Krogh, Lienert Jonas N, Krogh Marie Erskov, Stenspil Stine G, Dowds Mathias, Hansen Jonathan K S, Warming Christoffer, von Aufschnaiter Caroline, Pedersen Viktor Bliksted Roug, Wachtveitl Josef, Cacciarini Martina, Nielsen Mogens Brøndsted
Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen Ø, DK-2100, Denmark.
Institute of Physical and Theoretical Chemistry, Goethe University, Max-von-Laue-Straße 7, 60438, Frankfurt am Main, Germany.
Chemistry. 2025 May 22;31(29):e202501061. doi: 10.1002/chem.202501061. Epub 2025 Apr 27.
Multistate switches are interesting systems for a plethora of potential applications, such as for data storage involving many different states or for logic operations characterized by specific outputs. The main challenge is to achieve a precise control of accessibility to a specific state via a given sequence of multiple stimuli. Here, we have connected dihydroazulene (DHA) and spiropyran (SP) photoswitches in dyads to elucidate differences in optical and switching properties between ortho-, meta-, and para-phenylene-bridged dyads. Dyads were prepared by Suzuki and Sonogashira coupling reactions and photoisomerizations studied in detail by stationary and ultrafast spectroscopies. Moreover, the kinetics of thermal back-reactions of meta-stable states were studied. The results show path-dependent switchings of the dyads using light in combination with other stimuli (acid/base/heat), allowing access to eight distinct states. The accessibility to some specific states via only one sequence of external stimuli provides an additional degree of data storage-information is not only stored as the state itself but also as the unique sequence of stimuli required to reach this state. By changing the bridging unit between the photoswitches, various properties (outputs) were finely tuned such as absorption and fluorescence behaviors, lifetime of meta-stable state, and photoisomerization dynamics.
多态开关是用于大量潜在应用的有趣系统，例如用于涉及许多不同状态的数据存储或用于以特定输出为特征的逻辑运算。主要挑战在于通过给定的多个刺激序列实现对特定状态可达性的精确控制。在此，我们将二氢薁（DHA）和螺吡喃（SP）光开关连接成二元体，以阐明邻、间、对亚苯基桥连二元体在光学和开关特性上的差异。二元体通过铃木和 Sonogashira 偶联反应制备，并通过稳态和超快光谱详细研究了光异构化。此外，还研究了亚稳态热逆反应的动力学。结果表明，二元体利用光与其他刺激（酸/碱/热）结合进行路径依赖的开关，可实现八个不同状态。仅通过一个外部刺激序列就能访问某些特定状态，这提供了额外的数据存储维度——信息不仅存储为状态本身，还存储为达到该状态所需的独特刺激序列。通过改变光开关之间的桥连单元，可以精细调节各种特性（输出），如吸收和荧光行为、亚稳态寿命以及光异构化动力学。
