BOIMPY: Fluorescent Boron Complexes with Tunable and Environment-Responsive Light-Emitting Properties
BOIMPY: Fluorescent Boron Complexes with Tunable and Environment-Responsive Light-Emitting Properties
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DOI：
10.1002/chem.201603837
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发表时间：
2016-11-21
影响因子：
4.3
通讯作者：
Lee, Dongwhan
中科院分区：
文献类型：
--
作者：
Lee, Boran;Park, Byung Gyu;Lee, Dongwhan
以N-芳基亚氨基吡咯烷为配体，合成了一系列空气稳定的硼配合物1-5。作为特权BODIPY基序的极简结构模拟物设计，这些新的BOIMPY（亚胺吡咯烷配体的BOron络合物）荧光团具有低分子对称性，可促进CT型激发态的发射，具有大的斯托克斯位移和小的自猝灭。通过对化合物1-4的同源组的比较研究，我们已经证实，构象扭曲和供体-受体相互作用之间的微妙的相互作用决定了去激发的机制，其对溶剂极性以及质子化状态敏感地响应。在很宽的可见光谱范围内，BOIMPY分子的结构依赖性发光特性得到了很好的体现，即使在固态。为了利用CT型发射的环境敏感性，BOIMPY基序被进一步加工成生物探针分子5。活细胞荧光成像研究已经确定，5只局限于脂滴，产生良好的解决染色模式，而不影响细胞活力。这些发现为未来基于BOIMPY的功能分子在生物成像、化学传感和分子开关中的应用提供了希望。
A series of air-stable boron complexes 1-5 were prepared by using N-aryl iminopyrrolide ligands. Designed as minimalist structural mimics of the privileged BODIPY motif, these new BOIMPY (BOron complexes of IMinoPYrrolide ligands) fluorophores feature low molecular symmetry that promotes emission from CT-type excited states with large Stokes shifts and little self-quenching. Through comparative studies on the homologous set of compounds 1-4, we have confirmed that a delicate interplay between conformational twisting and donor-acceptor interaction dictates the mechanism of de-excitation, which responds sensitively to solvent polarity as well as protonation states. Over a wide visible spectral range, the structure-dependent light-emitting properties of BOIMPY molecules are well manifested, even in the solid-state. In order to exploit the environment-sensitive nature of CT-type emission, the BOIMPY motif was elaborated further into a bioprobe molecule 5. Live-cell fluorescence imaging studies have established that 5 is localized exclusively at lipid droplets to produce well-resolved staining patterns without affecting cell viability. These findings promise future elaboration of BOIMPY-based functional molecules for applications in biological imaging, chemical sensing, and molecular switching.