Partanen Iida, Belyaev Andrey, Su Bo-Kang, Liu Zong-Ying, Saarinen Jarkko J, Ibni Hashim Ishfaq, Steffen Andreas, Chou Pi-Tai, Romero-Nieto Carlos, Koshevoy Igor O
Department of Chemistry, University of Eastern Finland, Yliopistokatu 7, 80101, Joensuu, Finland.
Faculty of Chemistry and Chemical Biology, TU Dortmund University, 44227, Dortmund, Germany.
Chemistry. 2023 Aug 4;29(44):e202301073. doi: 10.1002/chem.202301073. Epub 2023 Jun 30.
Phosphonium-based compounds gain attention as promising photofunctional materials. As a contribution to the emerging field, we present a series of donor-acceptor ionic dyes, which were constructed by tailoring phosphonium (A) and extended π-NR (D) fragments to an anthracene framework. The alteration of the π-spacer of electron-donating substituents in species with terminal - PPh Me groups exhibits a long absorption wavelength up to λ =527 nm in dichloromethane and shifted the emission to the near-infrared (NIR) region (λ=805 nm for thienyl aniline donor), although at low quantum yield (Φ<0.01). In turn, the introduction of a P-heterocyclic acceptor substantially narrowed the optical bandgap and improved the efficiency of fluorescence. In particular, the phospha-spiro moiety allowed to attain NIR emission (797 nm in dichloromethane) with fluorescence efficiency as high as Φ=0.12. The electron-accepting property of the phospha-spiro constituent outperformed that of the monocyclic and terminal phosphonium counterparts, illustrating a promising direction in the design of novel charge-transfer chromophores.
鏻基化合物作为有前景的光功能材料受到关注。作为对这个新兴领域的贡献，我们展示了一系列供体-受体离子染料，它们是通过将鏻（A）和扩展的π-NR（D）片段定制到蒽骨架上构建而成的。在具有末端 -PPhMe基团的物种中，给电子取代基的π-间隔基的改变在二氯甲烷中表现出高达λ = 527 nm的长吸收波长，并将发射光谱转移到近红外（NIR）区域（对于噻吩基苯胺供体，λ = 805 nm），尽管量子产率较低（Φ < 0.01）。反过来，引入P-杂环受体显著缩小了光学带隙并提高了荧光效率。特别地，磷杂螺环部分能够实现近红外发射（在二氯甲烷中为797 nm），荧光效率高达Φ = 0.12。磷杂螺环成分的吸电子性能优于单环和末端鏻类似物，这说明了在新型电荷转移发色团设计中的一个有前景的方向。
