Time-resolved fluorescence offers many advantages over normal steady-state detection and becomes increasingly important in bioimaging. However, only very few fluorophores with emission in the visible range and fluorescence lifetimes above 5 ns are available. In this work, we prepare a series of new aza/oxa-triangulenium dyes where one of the usual oxa or aza bridges is replaced by an isopropyl bridge. This leads to a significant redshift of fluorescence with only moderate reductions of quantum yields and a unique long fluorescence lifetime. The fluorescence of the isopropyl bridged diazatriangulenium derivative CDATA⁺ is red-shifted by 50 nm (1400 cm⁻¹) as compared to the oxygen-bridged DAOTA⁺ chromophore and has intense emission in the red region (600–700 nm) with a quantum yield of 61%, and a fluorescence lifetime of 15.8 ns in apolar solution. When the CDATA⁺ dye is used as cell stain, high photostability and efficient time-gated cell imaging is demonstrated.

中文翻译：

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具有长荧光寿命和红色发射的碳桥联三角染料的设计，合成和时间门控细胞成像†

时间分辨荧光比常规稳态检测具有许多优势，并且在生物成像中变得越来越重要。但是，只有极少数的荧光团具有可见光范围内的发射，并且荧光寿命超过5 ns。在这项工作中，我们准备了一系列新的氮杂/氧杂-triangulenium染料，其中一种常见的氧杂或氮杂桥被异丙基桥取代。这导致荧光显着红移，而量子产率仅适度降低，并具有独特的长荧光寿命。与氧桥联的DAOTA ⁺相比，异丙基桥接的二氮杂三氮烯衍生物CDATA ⁺的荧光红移了50 nm（1400 cm ^-1）。发色团，在红色区域（600–700 nm）具有强发射，量子产率为61％，在非极性溶液中的荧光寿命为15.8 ns。当CDATA ⁺染料用作细胞染色剂时，证明了高光稳定性和高效的时间选通细胞成像。