Push-Pull-Type Polychlorotriphenylmethyl Radicals: New Two-Photon Absorbers and Dyes for Generation of Photo-Charges.
Push-Pull-Type Polychlorotriphenylmethyl Radicals: New Two-Photon Absorbers and Dyes for Generation of Photo-Charges.
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DOI：
10.1002/chem.201701875
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发表时间：
2017-06
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通讯作者：
Xiaojin Wu;J. Kim;Samara L. Medina;F. J. Ramírez;Paula Mayorga Burrezo;Shaofei Wu;Z. Lim;C. Lambert;J. Casado;Dongho Kim;Jishan Wu
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作者：
Xiaojin Wu;J. Kim;Samara L. Medina;F. J. Ramírez;Paula Mayorga Burrezo;Shaofei Wu;Z. Lim;C. Lambert;J. Casado;Dongho Kim;Jishan Wu
报道了三(4-碘-2，3，5，6-四氯苯基)甲烷(2)作为合成各种π共轭多氯三苯甲基自由基的通用结构单元。合成了三种不同取代方式的推拉型三苯胺取代的PTM自由基，它们都显示出强烈的价间电荷转移带和较大的双光子吸收(TPA)截面。此外，溶剂极性的增加也会导致TPA响应的改善。相关激发态的电荷转移特性在两性氧化还原特性和给体与受体之间的小耦合作用的驱动下，激发了电荷、PTM中的阴离子和胺臂中的阳离子的高效光产生。
Tri(4-iodo-2,3,5,6-tetrachlorophenyl)methane (2) is reported as a general building block for the synthesis of various π-conjugated polychlorotriphenylmethyl (PTM) radicals. Three push-pull-type triphenylamine-substituted PTM radicals with different substitution patterns were prepared and all exhibited intense inter-valence charge-transfer bands and large two-photon absorption (TPA) cross sections. Moreover, increase of solvent polarity also resulted in improved TPA response. The charge-transfer character of the relevant excited states provoked the efficient photo-generation of charges, anions in the PTM and cations in the amine arms, driven by the amphoteric redox character and the small coupling between donor and acceptor.