Experimental and Theoretical Studies of Quadrupolar Oligothiophene-Cored Chromophores Containing Dimesitylboryl Moieties as π-Accepting nEnd-Groups: Syntheses, Structures, Fluorescence, and One- and Two-Photon Absorption
Experimental and Theoretical Studies of Quadrupolar Oligothiophene-Cored Chromophores Containing Dimesitylboryl Moieties as π-Accepting nEnd-Groups: Syntheses, Structures, Fluorescence, and One- and Two-Photon Absorption
复制标题
DOI：
10.1002/chem.201402273
复制
发表时间：
2014-10-13
影响因子：
4.3
通讯作者：
Marder, Todd B.
中科院分区：
文献类型：
--
作者：
Ji, Lei;Edkins, Robert M.;Marder, Todd B.
通过钯催化的交叉偶联反应，以较高的产率(66-89%)合成了由四至五个末端含(E)-二甲基苯基乙烯基的噻吩环(4V-5V)、五个末端含两个芳基二甲基硼基的噻吩环(5B)以及含中心EDOT环的5V类似物(5VE)组成的四极低聚硫吩发色团。报道了4V、5B、联噻吩2V和5个噻吩衍生物的晶体结构。生色团4V、5V、5B和5VE的光致发光量子产率为0.26-0.29，高于较短的类似物1V-3V(0.01-0.20)和较短的荧光寿命(0.50-1.05 ns)。测量了2V-5V、5B和5VE在750-920 nm范围内的双光子吸收(TPA)谱。测量的2V-5V系列的TPA横截面随着长度的增加而稳步增加，最大可达1930 GM。我们比较了2V-5V与相关化合物5B和5VE的TPA性质，揭示了这类发色团的结构与性质的关系。DFT和TD-DFT结果，包括计算的TPA光谱，补充了实验结果，并有助于解释它们。与其他相关的噻吩基和二甲基硼基化合物的比较表明，我们的设计策略在合成双光子激发荧光应用的有效染料方面是很有前途的。
Quadrupolar oligothiophene chromophores composed of four to five thiophene rings with two terminal (E)-dimesitylborylvinyl groups (4V-5V), and five thiophene rings with two terminal aryldimesitylboryl groups (5B), as well as an analogue of 5V with a central EDOT ring (5VE), have been synthesized via Pd-catalyzed cross-coupling reactions in high yields (66-89%). Crystal structures of 4V, 5B, bithiophene 2V, and five thiophene-derived intermediates are reported. Chromophores 4V, 5V, 5B and 5VE have photoluminescence quantum yields of 0.26-0.29, which are higher than those of the shorter analogues 1V-3V (0.01-0.20), and short fluorescence lifetimes (0.50-1.05ns). Two-photon absorption (TPA) spectra have been measured for 2V-5V, 5B and 5VE in the range 750-920nm. The measured TPA cross-sections for the series 2V-5V increase steadily with length up to a maximum of 1930GM. We compare the TPA properties of 2V-5V with the related compounds 5B and 5VE, giving insight into the structure-property relationship for this class of chromophore. DFT and TD-DFT results, including calculated TPA spectra, complement the experimental findings and contribute to their interpretation. A comparison to other related thiophene and dimesitylboryl compounds indicates that our design strategy is promising for the synthesis of efficient dyes for two-photon-excited fluorescence applications.