Base-Assisted One-Pot Synthesis of N,N′,N"-Triaryltriazatriangulenium Dyes: Enhanced Fluorescence Efficiency by Steric Constraints
Base-Assisted One-Pot Synthesis of N,N′,N"-Triaryltriazatriangulenium Dyes: Enhanced Fluorescence Efficiency by Steric Constraints
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DOI：
10.1021/jo3007732
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发表时间：
2012-07-06
影响因子：
3.6
通讯作者：
Laursen, Bo W.
中科院分区：
文献类型：
--
作者：
Hammershoj, Peter;Sorensen, Thomas Just;Laursen, Bo W.
本文报道了阳离子N，N‘，N’‘-三芳基三氮杂三膦染料(Ar-3-TATA(+))的首次合成。以前，人们只知道烷基取代的三氮杂三钨衍生物(R-3-TATA(+))，这是由于苯胺在芳香族亲核取代反应中的低反应性导致了TATA(+)核的形成。在NaH存在下，通过加热三(2，6-二甲氧基苯基)甲基离子(DMP3C+)在不同的苯胺中合成了Ar-3-TATA(+)。在无溶剂反应中，尽管苯胺的反应活性较低，但所有三个芳基都可以被引入。合成了含Ar=苯基(2)、4-甲氧基苯基(3)和4-溴苯基(4)的对称Ar-3-TATA(+)衍生物。2和4的单晶结构为BF4-盐，其中TATA(+)生色团与芳基取代基之间的扭转角大于80。研究了其在溶液和薄膜中的光物理性质。结果表明，与母体烷基取代的R-3-TATA(+)盐相比，Ar-3-TATA(+)染料的荧光量子产率惊人地提高了3倍。Ar-3-TATA(+)染料具有高的量子产率(>；50%)和红光发射(lambda(Fl)=560 nm)，是超稳定的阳离子三角染料家族中一个很有前途的新成员。此外，合成的三溴衍生物4被证明是一种潜在的聚合物和其他大分子的三方合成子。
In this paper we report the first synthesis of cationic N,N',N ''-triaryltriazatriangulenium dyes (Ar-3-TATA(+)). Previously, only alkyl-substituted triazatriangulenium derivatives (R-3-TATA(+)) were known, a consequence of the low reactivity of anilines in the aromatic nucleophilic substitution reaction leading to the formation of the TATA(+) core. The synthesis of Ar-3-TATA(+) was achieved by heating the tris(2,6-dimethoxypheny)methylium ion (DMP3C+) in various anilines in the presence of NaH. In the solvent-free reaction all three aryl substituents could be introduced despite the low reactivity of the anilines. The symmetric Ar-3-TATA(+) derivatives with Ar = phenyl (2), 4-methoxyphenyl (3), and 4-bromophenyl (4) were synthesized. Single crystal structures of 2 and 4 were obtained as BF4- salts, where torsional angles larger than 80 were observed between the TATA(+) chromophore and the aryl substituents. The photophysical properties were studied in solution and in thin films. The results show that the Ar-3-TATA(+) dyes have a surprising 3-fold increase in fluorescence quantum yields when compared to the parent alkyl-substituted R-3-TATA(+) salts. With a high quantum yield (> 50%) and emission in the red (lambda(fl) = 560 nm) the Ar-3-TATA(+) dyes represent a promising new addition to the family of superstable cationic triangulenium dyes. Additionally, the synthesized tribromo derivative 4 is shown to be a potential triagonal synthon for polymers and other macromolecules.