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首页> 外文期刊>Chemistry: A European journal >2,2′:3′,2″-Terthiophene-based all-thiophene dendrons and dendrimers: Synthesis, structural characterization, and properties
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2,2′:3′,2″-Terthiophene-based all-thiophene dendrons and dendrimers: Synthesis, structural characterization, and properties

机译：2,2'：3'，2”-基于噻吩的全噻吩树枝状和树枝状大分子：合成，结构表征和性质

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摘要

The synthesis of generational dendritic oligothiophenes (DOTs) has been successfully achieved by a divergent/convergent approach that involves halogenation, boronation, and palladium-catalyzed Suzuki coupling reactions. The key point in the presented synthetic approach is the use of trimethylsilyl (TMS) protecting groups, which allow for the core-lithiation and subsequent boronation of the dendrons and for the peripheral ipso-substitution with iodine monochloride or N-bromosuccimide. In addition, the TMS protecting groups can be completely removed by using tetrabutylammonium fluoride, thus yielding only-thiophene-based dendrons and dendrimers. Due to their highly branched structure, all these synthesized DOTs are soluble in organic solvents. Chemical structures were confirmed by NMR spectroscopic, mass spectrometric, and elemental analysis. Concentration-dependent ~1H NMR spectroscopic investigations revealed that the higher generation compounds tend to aggregate in solution. Such an aggregation behavior was further confirmed by measuring with MALDI-TOF MS. Both MALDI-TOF MS and gel-permeation chromatography (GPC) analyses confirmed the monodispersity of the DOTs. Furthermore, GPC results revealed that these DOT molecules adopt a condensed globular molecular shape. Their optical and electronic properties were also investigated. The results indicated that these DOTs comprise various conjugated α-oligothiophenes with different chain lengths, which results in the higher generation compounds showing broad and featureless UV/Vis absorption spectra and ill-defined redox waves. Branching out all over: all-Thiophene dendrimers up to a fourth generation have been successfully synthesized by a divergent/convergent approach that involves halogenation, boronation, and Suzuki coupling reactions. These highly branched dendritic oligothiophenes are soluble in organic solvents and have a monodispersed nature (see scheme).
机译：已经通过发散/会聚方法成功地实现了世代树状寡聚噻吩（DOT）的合成，该方法涉及卤化，硼化和钯催化的Suzuki偶联反应。提出的合成方法中的关键点是使用三甲基甲硅烷基（TMS）保护基，该保护基可实现树枝化的核心锂化和随后的硼化，以及外围的ipso取代，包括一氯化碘或N-溴代琥珀酰亚胺。此外，通过使用四丁基氟化铵可以完全除去TMS保护基，从而仅产生基于噻吩的树枝状和树枝状聚合物。由于它们的高度支化结构，所有这些合成的DOT都可溶于有机溶剂。化学结构通过NMR光谱，质谱和元素分析确认。浓度依赖性的〜1H NMR光谱研究表明，更高世代的化合物倾向于在溶液中聚集。通过用MALDI-TOF MS测量进一步证实了这种聚集行为。 MALDI-TOF MS和凝胶渗透色谱（GPC）分析均证实了DOT的单分散性。此外，GPC结果表明，这些DOT分子采用了凝聚的球形分子形状。还研究了它们的光学和电子性质。结果表明，这些DOT包含各种具有不同链长的共轭α-低聚噻吩，这导致显示出更宽泛且无特征的UV / Vis吸收光谱和不确定的氧化还原波的高代化合物。全面分支：通过发散/收敛方法成功地合成了第四代全噻吩树枝状聚合物，该方法涉及卤化，硼化和Suzuki偶联反应。这些高度支化的树枝状低聚噻吩可溶于有机溶剂，并具有单分散性质（请参见方案）。

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