Analytical Application of Molecular Recognition by Photochemistry of Excited States

合成了分子中含有两个蒽单元的新型化合物，与聚醚结合。这些化合物在蒽环的激发态下识别分子或离子，在紫外光激发下，蒽环发生光二聚反应，形成三种区域异构体。通过加入碱土金属离子如钙离子改变区域异构体的比例。为了阐明这一现象，碱土金属离子的络合物形成常数进行了评估。然而，光度法如荧光或吸收光谱法导致光二聚化。采用~ 1H-NMR滴定法测定了生成常数。由形成常数的结果可知，在碱土金属离子中，钙离子形成的络合物最稳定。络合过程中的化学位移变化表明，钙配合物具有最适合光二聚反应的构象。含2-蒽类似物的化合物与钙离子有很强的络合能力，络合时荧光发射有较大的增强（40倍），并合成了含萘乙酰胺单元的新化合物。虽然在萘和酰胺之间插入了亚甲基单元，但萘的激发态已被淬灭，几乎没有观察到发射。这一现象可能是由TICT机制和PET（光诱导电子转移）机制共同作用的结果。该化合物与钙离子的络合诱导了萘部分的发射，并且这种发射是由络合物形成导致的TICT猝灭效率降低引起的。

New compounds which contain two anthracene units in the molecules combining with polyether were synthesized. These compounds will recognize molecules or ions at the excited state of the anthracene moieties.When these reagents are excited by UV light, the photo dimerization at anthracen rings occurred, and three regio-isomers formed. The ratio of the regio-isomers was changed by the addition of alkaline earth metal ions such as calcium ion. To elucidate this phenomenon, the complex formation constants for alkaline earth metal ions were evaluated. However, photometric method such as fluorescence or absorption spectrometry caused the photo dimerization. H-NMR titration method was adopted to evaluate the formation constants. From the result of formation constants, we found that calcium ion forms the most stable complex in alkaline earth metal ions. The chemical shift change at the complexation shows that the calcium complex takes the most suitable conformation for photo dimerization.A new compound which has two anthracene units linked to polyether via aromatic carboxamide moiety was synthesized. The compound with 2-anthracene analogue has large complexing ability with calcium ion, and shows large increase of fluorescence emission (40 fold) at the complexation.Tne new compounds which have naphthalene acetamide units was also synthesized. Although the methylene units was inserted between naphthalene and amide moietys, the excited state of naphthalene has been quenched and little emission was observed. This fact may be caused by combination of TICT mechanism and PET (photo induced electron transfer) mechanism. The conplexation of this compound with calcium ion induced an emission from naphthalene moiety, and this emission was caused from a decrease of TICT quenching efficiency by the complex formation.