Synthesis and properties of open-cage fullerene C60 derivatives: impact of the extended π-conjugation
Synthesis and properties of open-cage fullerene C60 derivatives: impact of the extended π-conjugation
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DOI：
10.1039/c7qm00449d
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发表时间：
2018-02-01
影响因子：
7
通讯作者：
Murata, Yasujiro
中科院分区：
文献类型：
--
作者：
Hashikawa, Yoshifumi;Yasui, Hidefumi;Murata, Yasujiro
我们已经发展了一种方法，用于合成具有扩展的π共轭轴承噻吩基团的开笼富勒烯C-60衍生物。通过将该方法应用于不对称二酮衍生物，可以在不改变分子式的情况下获得对称形式。为了研究不对称和对称形式的结构-性质关系，我们进行了电化学和电子物理测量。由于HOMO-LUMO能隙变窄，从非对称转变为对称时，紫外-可见吸收边移动了210 nm，电化学分析也证实了这一点。从理论计算，最长波长的吸收对称形式的主要贡献是分配到不寻常的分子内电荷转移跃迁，而π-π * 跃迁是占主导地位的不对称形式。
We have developed a method for the synthesis of open-cage fullerene C-60 derivatives with extended pi-conjugation bearing thienyl groups. By applying this method to an asymmetric diketo derivative, the symmetric form can be obtained without changing the molecular formula. To investigate the structure-property relationship for the asymmetric and symmetric forms, we conducted electrochemical and photophysical measurements. The UV-vis absorption edge was shifted by 210 nm upon changing from the asymmetric to the symmetric form due to the narrower HOMO-LUMO gap, which was also demonstrated by electrochemical analyses. From theoretical calculations, the major contribution of the longest wavelength absorption for the symmetric form is assignable to unusual intramolecular charge transfer transitions whereas pi-pi* transitions are dominant for the asymmetric form.