Paramagnetic Lanthanide NMR Probes Signalling Changes in Zinc Concentration by Emission and Chemical Shift: A Proof of Concept Study.
Paramagnetic Lanthanide NMR Probes Signalling Changes in Zinc Concentration by Emission and Chemical Shift: A Proof of Concept Study.
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DOI：
10.1002/chem.201900609
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发表时间：
2019-04
期刊：
影响因子：
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通讯作者：
Alice C Harnden;A. Batsanov;D. Parker
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文献类型：
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作者：
Alice C Harnden;A. Batsanov;D. Parker
一种基于修饰的DO3A大环配体与三吡啶胺(TPA)形成的稀土络合物的锌选择性探针在溶液和固态中进行了结构表征。一个吡啶基团具有叔丁基取代基作为核磁共振报告基团。单帽正方反棱柱Dy配合物与一个顶端的N原子(pKa 5.70Eu)有一个长键(2.83？)，并以锌键结合在一个水分子上。锌结合是可逆的，涉及所有外环配体N给体；它的信号是Eu发射强度的大(比率)变化，以及Tb、Dy和Tm络合物中顺磁移位的TBU共振的大小(>；50ppm)和化学位移的迹象。观察到缓慢的跨金属作用，导致形成一种特殊的双锌物种，其中一个锌离子是七配位的，另一个是六配位的。
A zinc-selective probe based on a set of rare earth complexes of a modified DO3A macrocyclic ligand incorporating a tris-pyridylamine (TPA) moiety has been structurally characterised in solution and in the solid-state. One pyridine group possesses a tert-butyl substituent to serve as an NMR reporter group. The mono-capped square-antiprismatic Dy complex has a long bond (2.83 Å) to an apical N atom (pKa 5.70 Eu) and binds to one water molecule on zinc binding. Zinc binding is reversible and involves all of the exocyclic ligand N donors; it is signalled by large (ratiometric) changes in Eu emission intensity, and by dramatic changes in the size (>50 ppm) and sign of the chemical shift of the paramagnetically shifted tBu resonances in Tb, Dy and Tm complexes. Slow trans-metallation was observed, leading to formation of an unusual di-zinc species in which one zinc ion is seven-coordinate and the other is six-coordinate.