Non-planar push-pull chromophores
Non-planar push-pull chromophores
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DOI：
10.1039/b926601a
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发表时间：
2010-01-01
影响因子：
4.9
通讯作者：
Diederich, Francois
中科院分区：
文献类型：
--
作者：
Kato, Shin-ichiro;Diederich, Francois
通过对缺电子烯烃如四氰基乙烯（TCNE）、7，7，8，8-四氰基对苯二酚二甲烷（TCNQ）和2，3，5，6-四氟-7，7，8，8-四氰基对苯二酚二甲烷的[2+ 2]环加成和环反转，开发了一类独特的非平面推挽发色团（F-4-TCNQ）以及二氰基乙烯基（DCV）和三氰基乙烯基（TCV）衍生物与给体取代炔的反应。这种高产率的“点击化学”型炔属树枝状聚合物转化提供了能够在窄电位范围内多电子吸收的树枝状电子汇。通过多炔齐聚物与TCNE和四硫富瓦烯（TTF）的一锅多组分级联反应，合成了具有树状烯主链的[AB]型齐聚物。在大多数情况下，所得到的发色团具有强烈的分子内电荷转移带，远延伸到近红外区域，其中一些显示高的三阶光学非线性。尽管被强供体取代，但新发色团中的吸电子部分仍然是有效的受体，并且其中许多发色团显示正的第一还原电位（相对于二茂铁/二茂铁（Fc（+）/Fc）对在CH 2Cl 2中），其与母体TCNE、TCNQ和F4-TCNQ的第一还原电位相媲美。与平面推挽类似物相比，发色团的非平面性强烈增强了它们的物理性质。它们具有高溶解度，热稳定性和升华性，这使得能够通过气相沉积形成非晶，高光学质量的薄膜，并使它们成为新型光电器件的先进功能材料。
The development of a unique class of non-planar push-pull chromophores by means of [2+ 2] cycloaddition, followed by cycloreversion, of electron-deficient olefins, such as tetracyanoethene (TCNE), 7,7,8,8-tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F-4-TCNQ), as well as dicyanovinyl (DCV) and tricyanovinyl (TCV) derivatives, to donor-substituted alkynes is explored in this feature article. This high-yielding, "click-chemistry''-type transformation with acetylenic dendrimers affords dendritic electron sinks capable of multiple electron uptake within a narrow potential range. An [AB]-type oligomer with a dendralene backbone was synthesised by a one-pot, multi-component cascade reaction of polyyne oligomers with TCNE and tetrathiafulvalene (TTF). In most cases, the resulting chromophores feature intense intramolecular charge-transfer bands extending far into the near infrared region and some of them display high third-order optical nonlinearities. Despite substitution with strong donors, the electron-withdrawing moieties in the new chromophores remain potent acceptors and a number of them display positive first reduction potentials (vs. the ferrocenium/ferrocene (Fc(+)/Fc) couple in CH2Cl2), which rival those of parent TCNE, TCNQ and F4-TCNQ. The non-planarity of the chromophores strongly enhances their physical properties when compared to planar push-pull analogues. They feature high solubility, thermal stability and sublimability, which enables formation of amorphous, high-optical-quality thin films by vapour phase deposition and makes them interesting as advanced functional materials for novel opto-electronic devices.