Amino group-driven distinguishing homocysteine from cysteine and glutathione in photoluminesecent signal of the iridium(III) complexes
Amino group-driven distinguishing homocysteine from cysteine and glutathione in photoluminesecent signal of the iridium(III) complexes
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DOI：
10.1016/j.saa.2021.120167
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发表时间：
2021-07-16
影响因子：
4.4
通讯作者：
Fu, Fengfu
中科院分区：
文献类型：
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作者：
Mu, Xiangjun;Tu, Rui;Fu, Fengfu
在这项工作中，设计、合成并表征了六种铱(III)配合物。通过单晶X射线衍射测定了配合物1（[（Pba）（2）Ir（bP-2N（CH3）（2））]PF6）、2（[（Pba）（2）Ir（bpy-2NH（2））]PF6）和3（[（pba）（2）Ir（bpy-2CH（3））]PF6）的分子结构。将 Hcy（同型半胱氨酸）添加到复合物 1 的溶液中后，肉眼观察到从橙红色到绿色的发光变化，对应于从 604 nm 到 498 nm（-106 nm）的大蓝移。而添加Cys（半胱氨酸）和GSH（谷胱甘肽）等其他常见氨基酸后，配合物1的发射强度几乎没有变化。配合物1的醛基与Hcy/Cys形成新的噻嗪烷/噻唑烷环，经H-1 NMR和高分辨率质谱证实。并且新产品1-Hey比1-Cys具有更高的量子产率。理论计算表明，1-Hey的HOMO（最高占据分子轨道）位于新形成的六元噻嗪环上，与1-Cys的HOMO不同。与其他铱(III)配合物相比，我们推测配合物1的较大蓝移和发射强度的增强与联吡啶配体上修饰的氨基具有较强的给电子能力有关。这将为今后基于比率的Hcy发光探针的设计提供思路。 (C) 2021 Elsevier B.V. 保留所有权利。
In this work, six iridium(III) complexes have been designed, synthesized and characterized. The molecular structures of complex 1 ([(Pba)(2)Ir(bP-2N(CH3)(2))]PF6), 2 ([(Pba)(2)Ir(bpy-2NH(2))]PF6) and 3 ([(pba)(2)Ir(bpy-2CH(3))]PF6) were determined by single crystal X-ray diffraction. Upon addition of Hcy (homocysteine) to the solution of complex 1, a luminescent variation from orange red to green was observed by the naked eye, corresponding to a large blue shift from 604 nm to 498 nm (-106 nm). While the emission intensity of complex 1 was almost no change after addition of other common amino acids including Cys (cysteine) and GSH (glutathione). The aldehyde group of complex 1 formed a new thiazinane/thiazolidine ring with Hcy/Cys confirmed by H-1 NMR and high-resolution mass spectrometry. And the new product 1-Hey had a higher quantum yield than 1-Cys. Theoretical calculations showed that the HOMO (highest occupied molecular orbital) of 1-Hey was located on the newly formed six-membered thiazinane ring, which was different from the HOMO of 1-Cys. Compared with the other iridium(III) complexes, we can speculate that the large blue shift and enhancement of the emission intensity of the complex 1 were related to the strong electron donating ability of the modified amino groups on bipyridine ligand. This will provide an idea for the design of ratio-based luminescence probes for Hcy in future. (C) 2021 Elsevier B.V. All rights reserved.