Conformationally restricted aza-bodipy: A highly fluorescent, stable, near-infrared-absorbing dye
Conformationally restricted aza-bodipy: A highly fluorescent, stable, near-infrared-absorbing dye
复制标题
DOI：
10.1002/anie.200461868
复制
发表时间：
2005-01-01
影响因子：
16.6
通讯作者：
Carreira, EM
中科院分区：
文献类型：
--
作者：
Zhao, WL;Carreira, EM
近年来，近红外吸收染料的制备和研究以及它们作为安全、非侵入性成像/对比探针的应用引起了人们极大的兴趣。[1-5]在近红外区域（700- 1100 nm）成像的优点很多，并已被广泛讨论。[2]这些优点中突出的是背景吸收、荧光和光散射的不存在或显著减少[6，7]，沿着低成本辐射源的可用性。与在可见光区吸收的发色团相比，红移近红外对应物的设计和合成遇到了问题，例如聚集、[3]光漂白[4]和低荧光量子产率。[4，5]迫切需要鉴定在NIR区域吸收和发射的更新，更有效的染料。在此，我们报道了一种高荧光（F= 0.28）、光稳定的氮杂-二吡咯亚甲基染料1，其在NIR区域（lmax= 740 nm）具有非常尖锐和强烈的吸收（半峰高全宽，fwhm= 30.4 nm; e= 159000）。此外，作为一种近红外吸收染料，F对溶剂极性不敏感，在整个浓度范围内（0.1-10 μm），吸收带保持清晰。二吡咯甲撑二氟化硼（difluoroboradiazas-indacene，bodipy）荧光染料已被广泛应用。[2，8-17]最近的努力集中在通过连接强供电子基团，[18]通过刚性化结构，[19]和通过扩展系统的共轭来将荧光发射调谐到bodipy核心的NIR区域。[20]这样的修饰可以导致具有大的红移吸收最大值的染料，但是这样的系统是否显示有用的荧光量子产率是值得怀疑的，因此它们的效用远不清楚。[21]此外，这些结构改变可能导致分子表现出不期望的性质;例如，被强供电子基团取代的结构显示出对溶剂的敏感性，这导致极性溶剂中的低F值作为电子转移的结果。[20 b]
There has been recent intense interest in the preparation and study of near-infrared (NIR)-absorbing dyes as well as their applications as safe, noninvasive imaging/contrasting probes.[1–5] The advantages of imaging in the NIR region (700–1100nm) are numerous and have been extensively discussed.[2] Prominent among these advantages is the absence or significant reduction of background absorption, fluorescence, and light scattering [6, 7] along with the availability of low-cost sources of irradiation. Compared to chromophores absorbing in the visible region, problems have been encountered in the design and synthesis of the red-shifted NIR counterparts, such as aggregation,[3] photobleaching,[4] and low fluorescence quantum yields.[4, 5] There is a pressing need for the identification of newer, more effective dyes that absorb and emit in the NIR region. Herein, we report a highly fluorescent (F= 0.28), photostable aza-dipyrromethene dye 1 with very sharp and intense absorption (full width at half maximum height, fwhm= 30.4 nm; e= 159000) in the NIR region (lmax= 740 nm). Additionally as a NIR-absorbing dye, F is not sensitive to solvent polarity, and the absorption band remains sharp throughout a range of concentrations (0.1–10 μm). Thus, 1 offers new opportunities for the use of such a dye in biological probes.The dipyrrometheneboron difluoride (difluoroboradiazas-indacene, bodipy) fluorescent dyes have found widespread applications.[2, 8–17] Recent efforts have been focused on tuning the fluorescence emission to the NIR region of the bodipy core by attaching strongly electron-donating groups,[18] by rigidifying the structure,[19] and by extending the conjugation of the system.[20] Such modifications can lead to dyes with large red-shifted absorption maxima, but it is questionable whether such systems display useful fluorescence quantum yields, and thus their utility is far from clear.[21] Moreover, these structural alterations can lead to molecules that exhibit undesired properties; for example, structures substituted with strongly electron-donating groups display sensitivity to solvents, which leads to low F values in polar solvents as a consequence of electron transfer.[20b]