Isoquinoline-Based TQEN Family as TPEN-Derived Fluorescent Zinc Sensors
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- 作者：Yuji Mikata ; Azusa Yamanaka ; Azusa Yamashita ; Shigenobu Yano
- 刊名：Inorganic Chemistry
- 出版年：2008
- 出版时间：August 18, 2008
- 年：2008
- 卷：47
- 期：16
- 页码：7295-7301
- 全文大小：304K
- 年卷期：v.47,no.16(August 18, 2008)
- ISSN：1520-510X
文摘
The hexadentate nitrogen ligands 1-isoTQEN (N,N,N’,N’-tetrakis(1-isoquinolylmethyl)ethylenediamine) and 3-isoTQEN (N,N,N’,N’-tetrakis(3-isoquinolylmethyl)ethylenediamine) have been prepared. The structures of these ligands are based on that of TPEN (N,N,N’,N’-tetrakis(2-pyridylmethyl)ethylenediamine). The introduction of a benzene ring into TPEN affords fluorescence ability upon zinc-ion binding. Compared to the quinoline isomer TQEN, isoquinoline derivatives 1-isoTQEN and 3-isoTQEN exhibit a lower-energy shift in the excitation and emission wavelengths and an enhanced fluorescence intensity, probably because of the energy-transfer mechanism between adjacent isoquinoline rings. Importantly, an increase in the Zn2+/Cd2+ discriminating ability and a reduction in the background fluorescence induced by pH were also achieved for isoquinoline derivatives. The zinc-ion-induced fluorescence of these isoTQENs was not quenched by an addition of TPEN, which demonstrates the significantly high zinc-ion binding ability of these isoTQEN ligands.