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    张融, 周颖, 晏琦帆. 分子内弱相互作用对共轭性的影响[J]. 华东理工大学学报(自然科学版), 2019, 45(6): 899-909. DOI: 10.14135/j.cnki.1006-3080.20180902001
    引用本文: 张融, 周颖, 晏琦帆. 分子内弱相互作用对共轭性的影响[J]. 华东理工大学学报(自然科学版), 2019, 45(6): 899-909. DOI: 10.14135/j.cnki.1006-3080.20180902001
    ZHANG Rong, ZHOU Ying, YAN Qifan. Influences of Intramolecular Weak Interactions on Conjugation[J]. Journal of East China University of Science and Technology, 2019, 45(6): 899-909. DOI: 10.14135/j.cnki.1006-3080.20180902001
    Citation: ZHANG Rong, ZHOU Ying, YAN Qifan. Influences of Intramolecular Weak Interactions on Conjugation[J]. Journal of East China University of Science and Technology, 2019, 45(6): 899-909. DOI: 10.14135/j.cnki.1006-3080.20180902001

    分子内弱相互作用对共轭性的影响

    Influences of Intramolecular Weak Interactions on Conjugation

    • 摘要: 以2,2对环蕃、三蝶烯、9,9’-螺二芴为连接单元,通过Buchwald-Hartwig/Suzuki偶联反应,连接富电子二苯氨基/缺电子萘酰亚胺片段,合成了化合物1~6和化合物7~12。在化合物1~67~12中,两个富电子中心或两个缺电子中心通过本共轭、交叉共轭、π-π堆积以及直接π-共轭方式连接。光物理和电化学测试表明,中性状态下基态共轭性以直接π-共轭最好,本共轭、交叉共轭次之,π-π堆积最差;在正离子自由基状态下共轭性以直接π-共轭最好,本共轭、交叉共轭次之且相近;负离子状态下共轭性则由于缺电子中心和连接单元之间的π-共轭作用被π-平面之间的扭转角削弱,化合物7~12中的连接方式都未能体现出差异。

       

      Abstract: Organic π-conjugated compounds have received great research attention due to their wide optoelectronic applications. Previous studies on tuning single molecular photoelectric properties of organic π-conjugated compounds focused on developing new π- skeletons and introducing electron-donating and withdrawing substituents. However, the influences of intramolecular weak interaction on the optoelectrical properties of organic π-conjugated compounds are lacking of study. Herein, we designed and synthesized compounds 1~6 and 7~12 via Buchwald-Hartwig/Suzuki coupling reactions, with 2,2paracyclophane (cyclophane), triptycene, and 9,9’-spirobifluorene (spirofluorene) as the linking units, two electron-rich diphenylamino or electron-deficient naphthalimide as the substituents. In compounds 1~6 and 7~12, the two electron-rich or electron-deficient centers interact with each other via homo-conjugation, cross-conjugation, π-π stacking, and π-direct conjugation. Photophysical and electrochemical measurements revealed that at neutral state, interactions (conjugation-effect) created by homo-conjugation in spirofluorene were lower than those created by direct π-conjugation, but were stronger than those created by cross-conjugation in spirofluorene, homo-conjugation in triptycene, and π-π stacking in cyclophane. When electron-rich compounds 1~6 lost one electron, converting into a monocation, conjugation effect decreases in the following order: Direct π-conjugation, homo-conjugation in spirofluorene, homo-conjugation in triptycene, cross-conjugation in spirofluorene. All these results demonstrated that optoelectronic properties of π-conjugated organic molecules could be tuned by the intramolecular weak interactions.

       

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