Synthesis, structure and spectroscopic properties of BODIPY dyes incorporating the pentafluorosulfanylphenyl group
Synthesis, structure and spectroscopic properties of BODIPY dyes incorporating the pentafluorosulfanylphenyl group
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含五氟硫基苯基的 BODIPY 染料的合成、结构及光谱性质
DOI：
10.1039/d3nj00633f
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发表时间：
2023
影响因子：
3.3
通讯作者：
James R
中科院分区：
文献类型：
--
作者：
James R
讨论了六个基于硼二吡咯亚甲基（BODIPY）核的化合物（BD 1-BD 6），并在meso位或3，5-位用五氟硫烷基芳基亚基官能化。芳环中的SF 5单元作为吸电子基团，并描述了其对BODIPY衍生物性能的影响。两种晶体结构得到的最简单的化合物中的内消旋位置的BODIPY是五氟硫基苯基（BD 1）或五氟硫基苯基乙炔基苯基（BD 2）。这两种结构的晶体堆积特征被用来合理化的激子耦合二聚体方面观察到的两种化合物的强固态发射。溶液相的化合物的物理性质也进行了描述，并在他们内部的趋势进行了讨论，在负超共轭和SF 5基团的“非键”共振效应。长波长吸收和荧光染料（BD 4-BD 6）在3，5位是π共轭的，但它们不显示与推挽发色团相关的典型溶剂化变色行为。其吸光度和荧光最大值随溶剂变化的变化与溶剂极化率函数（f（n2）=（n2 − 1）/（2n 2 + 1））充分拟合，其中n为折射率。良好的线性拟合支持基态和激发态之间的电子跃迁偶极矩没有重大变化。密度泛函理论（DFT）计算结果与局部低能π-π* 跃迁一致，而不是任何电荷转移跃迁，尽管存在吸电子SF 5基团。
Six compounds (BD1–BD6) are discussed based on the borondipyrromethene (BODIPY) core and functionalised in the meso position or the 3,5-positions with pentafluorosulfanylaryl subunits. The SF5 unit in the aryl ring acts an electron-withdrawing group and its effect on the properties of the BODIPY derivatives is described. Two crystal structures were obtained for the simplest compounds in which the meso position of the BODIPY is either pentafluorosulfanylphenyl (BD1) or pentafluorosulfanylphenylethynylphenyl (BD2). The crystal packing features of the two structures were used to rationalise the strong solid-state emission observed for the two compounds in terms of exciton-coupled dimers. Solution phase photophysical properties of the compounds are also described, and trends within them are discussed in terms of the negative hyperconjugation and the “non-bonded” resonance effect of the SF5 group. The long-wavelength absorbing and fluorescing dyes (BD4–BD6) are π-conjugated at the 3,5 positions, but they do not display typical solvatochromic behaviour associated with push–pull chromophores. The alterations in their absorbance and fluorescence maxima with change in solvent are adequately fitted to the solvent polarizability function (f(n2) = (n2 − 1)/(2n2 + 1)), where n is the refractive index. The good linear fit supports no major change in the electronic transition dipole moment between the ground and excited states. Density functional theory (DFT) calculations were consistent with localised low-energy π–π* transitions rather than any charge-transfer transitions despite the existence of the electron-withdrawing SF5 group(s).