Ishikawa Junichi, Sakamoto Hidefumi, Nakao Shintaro, Wada Hiroko
Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan, and Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama-shi, 640-8510, Japan.
J Org Chem. 1999 Mar 19;64(6):1913-1921. doi: 10.1021/jo9819584.
A dozen novel fluoroionophores have been synthesized which are polythiazaalkane and polythiaalkane derivatives coupled with an anthracene moiety by methyl, carbonyl, or methylphenylene bridging groups. The protonation and metal ion complexation behavior of analogues were examined in 1,4-dioxane-water solutions spectrophotometrically and spectrophotofluorometrically. The fluoroionophores, 1, 2, 5, and 6 contain basic nitrogen atoms and quench the fluorescence in the free forms because of photoinduced electron transfer (PET) from a nitrogen atom to a photoexcited anthracene unit. The fluorescence was recovered by the protonation on the nitrogen atom. The fluorescence intensities of the other fluoroionophores used here were not dependent on the pH of the solution. On the complexation of the protonated fluoroionophores 1, 2, 5, and 6 with metal ions under the acidic condition, the fluorescence intensities were decreased by the addition of silver ion selectively. Under the same conditions, the other fluoroionophores exhibited a decrease of the fluorescence intensity with the addition of silver ion selectively. These results imply that the fluoroionophores could form complexes and release a proton from the nitrogen atom of the protonated fluoroionophores. The quenching of the fluorescence of the complexed fluoroionophores 3, 4, 7, and 8-12 could be caused by the interaction of a silver ion with a pi-electron of the anthracene unit. The degree of spectral change on the complexation with silver ion is primarily dependent on the strength of the interaction of the bound silver ion with nitrogen atom, for 1, 2, 5, and 6, or with a pi-electron of the anthracene unit, for 3, 4, 7, and 8-12.
已经合成了十二种新型氟离子载体，它们是通过甲基、羰基或亚甲基桥基与蒽部分偶联的聚硫氮烷和聚硫烷衍生物。通过分光光度法和分光荧光法研究了类似物在1,4 - 二氧六环 - 水溶液中的质子化和金属离子络合行为。氟离子载体1、2、5和6含有碱性氮原子，由于从氮原子到光激发蒽单元的光诱导电子转移（PET），它们以游离形式淬灭荧光。氮原子上的质子化恢复了荧光。这里使用的其他氟离子载体的荧光强度不依赖于溶液的pH值。在酸性条件下，质子化的氟离子载体1、2、5和6与金属离子络合时，加入银离子会选择性地降低荧光强度。在相同条件下，加入银离子时，其他氟离子载体的荧光强度也会选择性降低。这些结果表明，氟离子载体可以形成络合物，并从质子化氟离子载体的氮原子上释放一个质子。络合的氟离子载体3、4、7和8 - 12的荧光淬灭可能是由于银离子与蒽单元的π电子相互作用引起的。与银离子络合时光谱变化的程度主要取决于结合的银离子与氮原子（对于1、2、5和6）或与蒽单元的π电子（对于3、4、7和8 - 12）相互作用的强度。
