Nitric oxide-induced fluorescence enhancement by displacement of dansylated ligands from cobalt
Nitric oxide-induced fluorescence enhancement by displacement of dansylated ligands from cobalt
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DOI：
10.1002/cbic.200600042
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发表时间：
2006-10-01
期刊：
影响因子：
3.2
通讯作者：
Lippard, Stephen J.
中科院分区：
文献类型：
--
作者：
Lim, Mi Hee;Kuang, Chaoyuan;Lippard, Stephen J.
本文报道了钴配合物[Co（Ds-AMP）（2）]（1）和[Co（Ds-AQ）（2）]（2），其中Ds-AMP和Ds-AQ分别与丹磺酰氨基甲基吡啶（Ds-HAMP）和丹磺酰氨基喹啉（Qs-HAQ）的共轭碱相连，合成了两个步骤，作为荧光基一氧化氮（NO）传感器，并通过X-射线衍射进行表征。射线晶体学与游离的Ds-HAMP或Ds-HAQ配体相比，两种复合物的荧光在CH 3CN或CHOH中显著猝灭。添加NO到1或2的CH 3CN溶液中，在35或20分钟内分别增强了2.1（+/-0.3）或3.6（+/-0.4）倍的积分荧光发射。将NO引入到络合物的甲醇溶液中，在7小时内，I的荧光增加了1.4（+/-0.1），2的荧光增加了6.5（+/-1.4）。这些研究表明，I和2可以监测NO的存在与打开发射，并且它们的荧光响应比先前报道的钴系统在配位溶剂如CH 3CN和CH 3OH中的那些更快。1H-1 NMR和IR光谱数据显示形成了[Co（NO）（2）}（10）钴-二亚硝酰基加合物，伴随着一个配体从钴中心解离，作为NO反应的含金属产物，结果表明NO诱导的配体释放是荧光增加的原因。
The cobalt complexes [Co(Ds-AMP)(2)] (1) and [Co(Ds-AQ)(2)] (2), where Ds-AMP and Ds-AQ ore the conjugate bases of dansyl aminomethylpyridine (Ds-HAMP) and dansyl aminoquinoline Qs-HAQ), respectively, were synthesized in two steps as fluorescence-based nitric oxide (NO) sensors and characterized by X-ray crystallography The fluorescence of the two complexes was significantly quenched in CH3CN or CHOH compared to that of the free Ds-HAMP or Ds-HAQ ligands. Addition of NO to a CH3CN solution of 1 or 2 enhanced the integrated fluorescence emission by factors of 2.1(+/- 0.3) or 3.6(+/- 0.4) within 35 or 20 min, respectively. Introduction of NO to methanolic solutions of the complexes similarly increased the fluorescence by 1.4(+/- 0.1) for I or 6.5(+/- 1.4) for 2 within 7 h. These studies demonstrate that I and 2 can monitor the presence of NO with turn-on emission and that their fluorescence responses are more rapid than those of previously reported cobalt systems in coordinating solvents such as CH3CN and CH3OH. H-1 NMR and IR spectroscopic data revealed the formation of a [Co(NO)(2)}(10) cobalt-dinitrosyl adduct with concomitant dissociation of one ligand from the cobalt center, as the metal-containing product of the NO reactions, a result indicating NO-induced ligand release to be the cause of the fluorescence increase.