Harada Mei, Kutsuna Misa, Kitamura Taichi, Usui Yusuke, Ujiki Masayoshi, Nakamura Yuka, Obata Tohru, Tanioka Masaru, Uchiyama Masanobu, Sawada Daisuke, Kamino Shinichiro
School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, 464-8650, Japan.
Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Chemistry. 2023 Oct 23;29(59):e202301969. doi: 10.1002/chem.202301969. Epub 2023 Sep 14.
We describe a π-topological transformation-based synthetic method for the preparation of a new type of near-infrared (NIR)-emissive rhodamine dye called Polymethine-embedded Rhodamine Fluorophore (PeR Fluor). In contrast to conventional NIR-emissive dyes that require tedious synthetic steps and/or a high cost, linear fully π-conjugated PeR Fluor can be regioselectively prepared in one step by mixing different nucleophiles with ABPXs, a family of rhodamines with a cross-conjugated structure. PeR Fluor exhibits bright NIR fluorescence emission and high photostability owing to the cooperative π-electron system of rhodamines and polymethine scaffolds. Large bathochromic shifts of the absorption and fluorescence emission maxima can be achieved by modifying the N-substituted group to obtain NIR-absorbing/emitting PeR Fluor. We also demonstrate the stimulus-responsive functionality of PeR Fluor through the addition of chemicals (acid/base), which shows switchable NIR and visible fluorescence response. Our π-topological transformation-based synthetic method is a promising approach to produce new functionalized rhodamine dyes.
我们描述了一种基于π-拓扑变换的合成方法，用于制备一种新型的近红外（NIR）发射罗丹明染料，称为聚甲炔嵌入罗丹明荧光团（PeR Fluor）。与需要繁琐合成步骤和/或高成本的传统近红外发射染料不同，线性全π共轭的PeR Fluor可以通过将不同的亲核试剂与ABPXs（一类具有交叉共轭结构的罗丹明）混合，一步区域选择性地制备。由于罗丹明和聚甲炔支架的协同π电子体系，PeR Fluor表现出明亮的近红外荧光发射和高光稳定性。通过修饰N-取代基以获得近红外吸收/发射的PeR Fluor，可以实现吸收和荧光发射最大值的大的红移。我们还通过添加化学物质（酸/碱）证明了PeR Fluor的刺激响应功能，其显示出可切换的近红外和可见荧光响应。我们基于π-拓扑变换的合成方法是生产新型功能化罗丹明染料的一种有前途的方法。
