Mirror‐Image Cofacial Coronene Dimers Characterized by CD and CPL Spectroscopy: A Twisted Bilayer Nanographene
Mirror‐Image Cofacial Coronene Dimers Characterized by CD and CPL Spectroscopy: A Twisted Bilayer Nanographene
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DOI：
10.1002/cptc.202100166
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发表时间：
2021-09
期刊：
影响因子：
3.7
通讯作者：
Keiji Uehara;Haruka Kano;Kyohei Matsuo;H. Hayashi;M. Fujiki;H. Yamada;N. Aratani
中科院分区：
文献类型：
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作者：
Keiji Uehara;Haruka Kano;Kyohei Matsuo;H. Hayashi;M. Fujiki;H. Yamada;N. Aratani
双层石墨烯（BLG）的电子性质随晶面间距和旋转角度的变化而发生显著变化，是目前研究的热点。我们成功地合成了离散的BLG模型，通过桥接两个晕苯与1，8-萘键（C2）。由于大的旋转能，C2的顺式和反式阻转异构体可以被分离。X-射线衍射分析表明，C2 S为AB型堆积，C2 A为手性扭曲双层石墨烯（TBG）型。因此，C2的反式被光学解析，并通过圆二色性（CD）和圆偏振发光（CPL）光谱进行表征。在最长吸收波长处的CD谱中观察到Cotton效应，并观察到相应的双信号CPL谱。不对称因素|闷闷不乐|在435 nm和450 nm处，C2 A的平均值分别为2.0×10− 3 和1.2×10− 3 。
Bilayer graphene (BLG), which changes its electronic properties significantly depending on the interplanar distance and rotation angle, is a hot research topic. We successfully synthesized discrete BLG models by bridging two coronenes with a 1,8‐naphthalene linkage (C2). Owing to the large rotational energy, thesyn‐ andanti‐atropisomers ofC2could be isolated. X‐ray crystallographic analysis revealed that thesyn‐form (C2S) is an AB stacking type and theanti‐form (C2A) is a chiral twisted bilayer graphene (TBG) type. Therefore, theanti‐form ofC2was optically resolved and characterized by circular dichroism (CD) and circularly polarized luminescence (CPL) spectroscopy. The Cotton effect was observed in the CD spectra at the longest absorption wavelength, and the corresponding bisignate CPL spectra were observed. The dissymmetry factors |glum| ofC2Awere found to be 2.0×10−3at 435 nm and 1.2×10−3at 450 nm.