Ikeda Taichi, Saha Sourav, Aprahamian Ivan, Leung Ken C-F, Williams Adides, Deng Wei-Qiao, Flood Amar H, Goddard William A, Stoddart J Fraser
The California NanoSystems Institute, USA.
Chem Asian J. 2007 Jan 8;2(1):76-93. doi: 10.1002/asia.200600355.
Encouraged by the prospect of producing an electrochemical, color-switchable red-green-blue (RGB) dye compound, we have designed, synthesized, and characterized two three-station [2]catenanes. Both are composed of macrocyclic polyethers containing three pi-electron-rich stations, which act as recognition sites for a pi-electron-deficient tetracationic cyclophane. The molecular structures of the two three-station [2]catenanes were characterized fully by mass spectrometry and 1H NMR spectroscopy. To anticipate the relative occupancies of the three stations in each [2]catenane by the cyclophane, model compounds with the same constitutions in the vicinity of the stations were synthesized. The relative ground-state populations of the three stations occupied in both [2]catenanes were estimated from the thermodynamic parameters for 1:1 complexes between all these model compounds and the cyclophane, obtained from isothermal titration calorimetry (ITC). The electrochemical and electromechanical properties of the three-station [2]catenanes were analyzed by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and spectroelectrochemistry (SEC). The first three-station [2]catenane was found to behave like a bistable system, whereas the second can be described as a quasi-tristable system.
受生产一种电化学、颜色可切换的红绿蓝（RGB）染料化合物前景的鼓舞，我们设计、合成并表征了两种三站点[2]连环烷。两者均由含有三个富π电子站点的大环聚醚组成，这些站点充当缺π电子四环番的识别位点。通过质谱和1H NMR光谱对这两种三站点[2]连环烷的分子结构进行了全面表征。为了预测环番在每个[2]连环烷中三个站点的相对占有率，合成了在站点附近具有相同组成的模型化合物。根据等温滴定量热法（ITC）获得的所有这些模型化合物与环番之间1:1配合物的热力学参数，估算了两种[2]连环烷中被占据的三个站点的相对基态丰度。通过循环伏安法（CV）、差分脉冲伏安法（DPV）和光谱电化学（SEC）分析了三站点[2]连环烷的电化学和机电性能。发现第一个三站点[2]连环烷表现得像一个双稳态系统，而第二个可以描述为准三稳态系统。
