Argonne-Northwestern Solar Energy Research (ANSER) Center and Center for the Chemistry of Integrated Systems (CCIS), Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113 (USA).
Angew Chem Int Ed Engl. 2015 Oct 5;54(41):11971-7. doi: 10.1002/anie.201504576. Epub 2015 Aug 20.
Understanding electronic communication among multiple chromophoric and redox units requires construction of well-defined molecular architectures. Herein, we report the modular synthesis of a shape-persistent chiral organic square composed of four naphthalene-1,8:4,5-bis(dicarboximide) (NDI) sides and four trans-1,2-cyclohexanediamine corners. Single crystal X-ray diffraction reveals some distortion of the cyclohexane chair conformation in the solid state. Analysis of the packing of the molecular squares reveals the formation of highly ordered, one-dimensional tubular superstructures, held together by means of multiple [CH⋅⋅⋅OC] hydrogen-bonding interactions. Steady-state and time-resolved electronic spectroscopies show strong excited-state interactions in both the singlet and triplet manifolds. Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectroscopies on the monoreduced state reveal electron sharing between all four NDI subunits comprising the molecular square.
理解多个发色团和氧化还原单元之间的电子通信需要构建定义良好的分子架构。在此，我们报告了由四个萘 1,8:4,5-双（二羧酸二酰亚胺）（NDI）边和四个反式 1,2-环己二胺角组成的具有形状保持的手性有机正方形的模块化合成。单晶 X 射线衍射显示出在固态中环己烷椅构象的一些变形。分子正方形的堆积分析表明形成了高度有序的一维管状超结构，通过多个 [CH⋅⋅⋅OC]氢键相互作用结合在一起。稳态和时间分辨电子光谱显示在单重态和三重态中都存在强烈的激发态相互作用。单还原态的电子顺磁共振（EPR）和电子-核双共振（ENDOR）光谱显示组成分子正方形的四个 NDI 亚基之间的电子共享。
