本論文報導三個系列的化合物(1~3)之合成並研究其在高極性溶劑中是否有定域化激發態(LE)-分子內電荷轉移態(ICT)的雙螢光現象。系列一的化合物為1OMe、1CN和1EE，系列二的化合物為2OMe和2CN，系列三的化合物為3H和3CN。由於第二和第三系列化合物的結構中含有雙吡啶胺基(dpa)接受區，因此我們也探討其與金屬離子的螢光感應行為。 螢光光譜顯示化合物1OMe、1EE、2CN及3CN具有雙螢光的現象，由化合物1EE證明電子予體中不一定需要有芳香胺才會產生ICT的螢光。先前實驗室曾合成出化合物1H，其有ICT的螢光且與鋅離子錯合後ICT放射峰有紅位移現象，因此我們設計化合物系列二，探討電子受體在具有對位的強推或強拉電子基取代時，是否會影響ICT螢光的生成及與金屬離子感應行為。結果顯示化合物2CN有ICT螢光而2OMe則無，且化合物2CN對過渡金屬離子的螢光感應為ICT螢光強度下降，LE螢光強度上升，若以LE/ICT螢光強度比值的增加量作標準，其對鋅與鎳離子有較大變化。當我們將二苯乙烯之雙鍵以架橋的方式固定後(即3CN)，其LE/ICT螢光感應的靈敏度與選擇性均有提升。 This thesis reports the synthesis and fluorescence properties of three compounds series (1-3). We are particularly interested in the structural dependence of dual fluorescence behavior of 1-3 in polar solvents. Because of the ionophoric nature of the dipyridylamino (dpa) group in 2OMe, 2CN, 3H and 3CN, their fluoroionophoric behavior was also investigated. The fluorescence spectra of 1EE as well as 1OMe, 2CN, and 3CN show dual fluorescence in acetonitrile, which indicates that both arylamino and alkylamino electron donors can lead to intramolecular charge transfer (ICT) fluorescence in these stilbene-methylene-amino systems. When compared with compound 1H, one of our previously investigated fluoroionophores, 2OMe and 2CN are its derivatives with an electron-donating methoxy and electron-withdrawing cyano group at the stilbene para position, respectively. While 1H and 2CN are dual fluorescent, 2OMe only displays the locally-excited (LE) fluorescence. In addition, 1H undergoes a red shift of the ICT fluorescence in response to Zn(II), but the LE fluorescence of 2OMe decreases and the LE fluorescence of 2CN increases at the expense of the ICT fluorescence under the same conditions. Apparently, the fluoroionophoric behavior of 2OMe and 2CN is different from that of 1H. Compound 2CN selectively recognizes Zn(II) and Ni(II) among eight transition metal ions in terms of the relative enhancement of the LE/ICT intensity ratio. When the torsion of the central double bond is restricted, as is the case of 3CN, both the sensitivity and selectivity of the LE/ICT fluorescene response toward transition metal ions are improved in comparison to that of 2CN.
