A.N. Nesmeyanov Institute of Organoelemnt Compounds of Russian Academy of Sciences, 119334 Moscow, Russian Federation.
Photochemistry Center, FSRC "Crystallography and Photonics" of Russian Academy of Sciences, 119421 Moscow, Russian Federation.
J Phys Chem B. 2023 Jul 6;127(26):5881-5898. doi: 10.1021/acs.jpcb.3c02300. Epub 2023 Jun 22.
A series of new tetrachromophoric systems based on stereoregular tetracyclosiloxanes and dibenzoylmethanatoboron difluoride derivatives have been synthesized and characterized by a complex of physicochemical methods. The photophysical properties of the synthesized compounds are studied by electronic absorption, steady-state, and time-resolved fluorescence spectroscopy. In the synthesized compounds, four dibenzoylmethanatoboron difluoride (DBMBF)-based fluorophores are in an all-cis arrangement with respect to a cyclotetrasiloxane scaffold. DFT calculations predict that they can form H-type dimers, trimers, or tetramers with an antiparallel orientation of their ground-state dipole moments. Under UV excitation, solutions of these compounds in polar and nonpolar solvents exhibit complex fluorescence consisting of monomer- and excimer-like emissions with different lifetimes. Global fitting analysis reveals the presence of at least four kinetically distinguishable species in the excited state. The studied compounds in solutions have CIE chromaticity coordinates very close to the white color point and are promising objects for the development of next-generation single-emission materials for white illumination.
一系列基于立体规整的四环硅氧烷和二苯甲酰甲烷二氟化硼衍生物的新型四色化合物已通过一系列物理化学方法进行了合成和表征。通过电子吸收、稳态和时间分辨荧光光谱研究了合成化合物的光物理性质。在合成的化合物中，四个二苯甲酰甲烷二氟化硼（DBMBF）基荧光团相对于环四硅氧烷支架呈全顺式排列。DFT 计算预测它们可以形成具有反平行排列的基态偶极矩的 H 型二聚体、三聚体或四聚体。在紫外光激发下，这些化合物在极性和非极性溶剂中的溶液表现出复杂的荧光，包括单体和激基缔合物样发射，具有不同的寿命。全局拟合分析表明，在激发态中至少存在四种动力学上可区分的物种。溶液中的研究化合物具有非常接近白色色点的 CIE 色度坐标，是开发下一代用于白色照明的单发射材料的有前途的对象。
