Janiga Anita, Bednarska Dominika, Thorsted Bjarne, Brewer Jonathan, Gryko Daniel T
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka, 44/52 01-224, Warsaw, Poland.
Org Biomol Chem. 2014 May 14;12(18):2874-81. doi: 10.1039/c4ob00143e.
The synthesis and optical characterization of six novel heteroaromatic-based chromophores is described. The new dyes present mostly an A-D-A general framework, where A is an electron-deficient aromatic ring and D is an electron-rich pyrrolo[3,2-b]pyrrole moiety, linked via triple bonds. It was demonstrated that the increase in the molecular length of the chromophore effectively extends π-conjugation. The effect of structural variations on photophysical properties was studied in detail for these compounds and the relationship between the structure and photophysical properties was thoroughly elucidated by comparison with simpler tetraaryl-analogues. The strong charge-transfer characteristic of these functional dyes can be illustrated by large Stokes shifts (4100-7100 cm(-1)) for A-D-A architectures. The replacement of phenyl rings at positions 2 and 5 with the arylethynylaryl substituents bathochromically shifts both absorption and emission at ca. 50-150 nm. The clear dependence of fluorescence maxima on the electron-accepting property of the peripheral arylethynyl substituent emphasizes strong π-conjugation in these molecules. The donor-acceptor interactions were also found to influence the two-photon absorption properties.
描述了六种新型基于杂芳烃的发色团的合成及光学表征。这些新型染料大多呈现A-D-A通用框架，其中A是缺电子芳环，D是富电子的吡咯并[3,2-b]吡咯部分，通过三键相连。结果表明，发色团分子长度的增加有效地扩展了π共轭。详细研究了结构变化对这些化合物光物理性质的影响，并通过与更简单的四芳基类似物比较，全面阐明了结构与光物理性质之间的关系。对于A-D-A结构，这些功能性染料的强电荷转移特性可通过大的斯托克斯位移（4100 - 7100 cm⁻¹）来说明。在2和5位用芳基乙炔基芳基取代基取代苯环，使吸收和发射都发生约50 - 150 nm的红移。荧光最大值对外围芳基乙炔基取代基的电子接受性质的明显依赖性强调了这些分子中强烈的π共轭。还发现供体-受体相互作用会影响双光子吸收性质。
