螺旋烯
直接的
化学
氧化还原
单重态
分子线
共轭体系
咔唑
开壳
环烯
环番
电子结构
电致变色
电子转移
分子开关
光化学
结晶学
计算化学
分子
晶体结构
有机化学
聚合物
物理化学
激发态
物理
电极
核物理学
作者
Yafei Shi,Chenglong Li,Jiaqi Di,Yuting Xue,Yawei Jia,Jiaxian Duan,Xiao‐Yu Hu,Yu Tian,Yanqiu Li,Chen Sun,Niu Zhang,Yujie Xiong,Tianyun Jin,Pangkuan Chen
标识
DOI:10.1002/anie.202402800
摘要
π‐Conjugated chiral nanorings with intriguing electronic structures and chiroptical properties have attracted considerable interests in synthetic chemistry and materials science. We present the design principles to access new chiral macrocycles (1 and 2) that are essentially built on the key components of main‐group electron‐donating carbazolyl moieties or the π‐expanded aza[7]helicenes. Both macrocycles show the unique molecular conformations with a (quasi) figure‐of‐eight topology as a result of the conjugation patterns of 2,2’,7,7’‐spirobifluorenyl in 1 and triarylamine‐coupled aza[7]helicene‐based building blocks in 2. This electronic nature of redox‐active, carbazole‐rich backbones enabled these macrocycles to be readily oxidized chemically and electrochemically, leading to the sequential production of a series of positively charged polycationic open‐shell cyclophanes. Their redox‐dependent electronic states of the resulting multispin polyradicals have been characterized by VT‐ESR, UV−vis−NIR absorption and spectroelectrochemical measurements. The singlet (ΔES‐T = ‒1.29 kcal mol‒1) and a nearly degenerate singlet‐triplet ground state (ΔES‐T(calcd) = ‒0.15 kcal mol‒1 and ΔES‐T(exp) = 0.01 kcal mol‒1) were proved for diradical dications 12+2• and 22+2•, respectively. Our work provides an experimental proof for the construction of electron‐donating new chiral nanorings, and more importantly for highly charged polyradicals with potential applications in chirospintronics and organic conductors.
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