Synthesis and optical properties of the isomeric pyrimidine and carbazole derivatives: Effects of polar substituents and linking topology
作者:Lina Skardziute、Jelena Dodonova、Andzejus Voitechovicius、Justina Jovaisaite、Regimantas Komskis、Asta Voitechoviciute、Jonas Bucevicius、Karolis Kazlauskas、Saulius Jursenas、Sigitas Tumkevicius
DOI:10.1016/j.dyepig.2015.03.008
日期:2015.7
intramolecular charge transfer (ICT) character of the excited states, which was proved by solvatochromic dynamics and supported by DFT calculations. ICT resulted in the dramatic enhancement of excited state lifetime (up to 5 times) with increased solvent polarity. The competition of constantly decreasing radiative and nonradiative relaxation rates resulted in non-monotonous variation of fluorescence
通过将相应的2,4-或4,6-二氯嘧啶依次进行Suzuki偶联,成功合成了一系列以嘧啶单元为中心核和在嘧啶环的2、4和4、6、6位含芳基的咔唑的非线性低聚亚芳基。在不同极性的介质中彻底研究了化合物的光学性质。由于嘧啶核具有显着的电子接受特性,带有咔唑基团的化合物表现出激发态的分子内电荷转移(ICT)特征,这通过溶剂变色动力学得到证明并得到DFT计算的支持。ICT通过增加溶剂极性极大地提高了激发态寿命(高达5倍)。不断降低的辐射弛豫率和非辐射弛豫率的竞争导致荧光量子产率从24%到74%的非单调变化。讨论了通过改变取代基的连接拓扑和极性来调整嘧啶衍生物的荧光量子产率。