本論文乃利用「胺基共軛效應」的原理來研究mAS、DMAS兩系列分子發螢光之分子內電荷轉移(ICT)態之結構，並利用取代基效應設計新型螢光感應分子CPAS-crown、DDCM-crown。「胺基共軛效應」主要是由於N-苯基共軛取代導致反式二苯乙烯胺上的光異構化反應速率變慢，因而造成高螢光量子產率的特性。 為了瞭解取代基效應對mAS、DMAS兩系列分子ICT態結構的影響，我們合成了一系列在N-苯基上含取代基的化合物。由螢光圖譜和螢光量子產率的溶劑效應，我們推斷mAS-OMe與DMAS-CN兩分子在乙腈中可能具有TICT態。 本實驗室曾設計出化合物PAS-crown做為螢光離子的感應分子，本論文則探討CPAS-crown和DDCM-crown分子的螢光離子感應效果。結果顯示CPAS-crown分子對Mg2+離子於乙腈溶劑下較PAS-crown有較高選擇性與靈敏度而DDCM-crown感應效果不佳。由DDCM-OMe和DDCM-MeOMe顯示DDCM-crown與金屬離子鍵結前後並未改變ICT態結構。 The goal of this thesis is to investigate the excited state conformations of fluorescent mAS and DMAS molecules on the basis of the amino conjugation effect. New fluorescent probes CAPS-crown and DDCM-crown was also designed base on the substituent-depent ICT behavior of trans-4-(N-arylamino)stilbenes . The amino conjugation effect in N-aryl substituted trans-4-aminostilbenes increase the barrier for the double bond torsion and thus decrease the photoisomerization quantum yield and increace the fluorescence quantum yield. To understand the influence of substituants on the conformations of mAS, DMAS in the excited state, we have synthesized a series of N-aryl substituted analogues. The plots of the fluorescence quantum yield against the solvent polarity suggests the existence of a TICT state for mAS-OMe and DMAS-CN in acetonitrile. PAS-crown was previously designed as a fluorescent probe for cations. For comparison, the corresponding sensing ability of CPAS-crown and DDCM-crown has been investigated and reported in this thesis. CAPS-crown is more selective and also more sensitive than PAS-crown towards Mg2+, where DDCM-crown shows a relatively poor cation-sensing ability. According to the behavior of DDCM-OMe and DDCM-MeOMe, cation-binding of DDCM-crown does not affect the structure of its ICT state.
