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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/6095


    Title: 含胺基之二苯乙烯衍生物之光異構化;行為與螢光感應行為之研究 Substituent-Dependent Activation Parameters and Fluorionophoric behavior in N-Aryl-Substituted trans-4-Aminostilbenes
    Authors: 黃中煜;Chung-Yu Hwang
    Contributors: 化學研究所
    Keywords: 芐冠醚;本質型;二苯乙烯;異構化;螢光;離子感應;TICT;Fluoroscence;crown ether;cation;Aminostilbene
    Date: 2008-01-15
    Issue Date: 2009-09-22 10:13:09 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 本論文其分三大部分,第一部份是根據ICT原理設計並合成出數種本質型螢光離子感應分子系列1B和2B,結構以芐冠醚(B12C4、B15C5和B18C6)作為金屬離子接受器。為了更深入了解本實驗室先前所提出的取代基對等行為,我們也設計了化合物1DF和2DF。在乙腈中化合物1B4~1B6、2B4~2B6與ⅡA族金屬離子錯合後螢光與吸收光譜皆有紅位移現象。僅有錯合物1B5/ⅡA與2B5/ⅡA可與化合物1DF和2DF有取代基對等現象。在二氯甲烷中化合物1B4~1B6、2B4~2B6對ⅠA族金屬離子、1B6與2B6對ⅡA族金屬離子,亦可與1DF和2DF有取代基對等現象。亦即雙氟原子取代基可以等於芐冠醚錯合金屬離子後光譜行為,包含螢光、吸收光譜、螢光生命期和螢光量子產率。此結果顯示感應錯合物在激發態時,金屬離子仍然存在於接受器之內。此對等關係除了對於本質型螢光感應分子設計有幫助外,更能藉此深入了解金屬離子感應的超分子行為與機制。 本論文第二部分為具有胺基(芐冠醚)之二苯乙烯感應分子3B5和4B5之合成與螢光感應之研究。在乙腈中兩者對ⅡA族金屬離子具選擇性,感應的訊號具有類似PET機制的特點,螢光驟滅與增強變化能具有辦別訊號開-關的作用,其感應機制是藉由扭轉分子內電荷轉移(TICT)與平面分子內電荷轉移(PICT)來達成。當化合物3B5和4B5在乙腈酸性環境之中會有質子化現象(3B5/H+和4B5/H+),僅表現出二苯乙烯的螢光性質,但加入金屬離子後即可去質子化現象,並且具有雙重螢光訊號相互消長的特點。本研究除對於TICT機制有更加了解並提供感應分子的設計契機。 本論文第三部分為研究具有推(拉)雙取代之二苯乙烯胺分子DS與DCS系列化合物,藉變溫螢光生命期實驗方法,研究在甲基環己烷和乙腈中的扭轉雙鍵能障(Ea)、溶劑的溶合效應(logA)和激發態去活化速率(∑k、kfl和kd)相互關聯性。在極性溶劑中,隨著N-苯環取代基數的增加Ea值會變小。比較極性與非極性溶劑之中的Ea 和logA數值,可推知扭轉結構之激發態1p*態與順式結構之激發態1t*態間相對的分子極性。此研究結果使我們對二苯乙烯胺的1p*態有進一步了解。 In this thesis, we report the design and synthesis of two ICT-based intrinsic fluoroionophore series of trans-4- aminostilbenes (1B and 2B). The 1,2-difluor-/fluoroionophoric behavior of the benzo-12-crown-4- (B12C4) and benzo-15-crown-5- (B15C5) and benzo-18-crown-6- (B18C6) -derived species (1B4-1B6 and 2B4-2B6) in acetonitrile and dichloromethane are also investigated. Great similarities in electronic spectroscopic properties (chemical shifts, wavelength, intensity, and lifetime) between the metal ion-complexed supermolecules and the corresponding 1,2-difluor-substituted molecules have been observed: namely, 1B5/ⅡA and 2B5/ⅡA~1DF and 2DF in acetonitrile and 1B4/ⅠA -1B6/ⅠA ~ 2B4/ⅠA -2B6/ⅠA ~ 1B6/ⅡA- 2B6/ⅡA ~ 1DF and 2DF in dichloromethane. Such spectroscopic correlations allow us to define the metal ion-modulated electronic character of the benzocrown oxygen atom in the ground and excited states and, in turn, to gain insights into the observed fluoroionophoric behavior of these probes in terms of the size and direction of fluorescence shifts and intensity variations. Amino-based fluoroionophores 3B5 and 4B5 can selectively sense alkaline earth metal ions in MeCN under both neutral and acidic conditions by different signaling mechanisms. The fluoroionophoric behavior for the neutral probes is characterized by an ‘off–on’ photoinduced electron transfer (PET)-like fluorescence intensity response due to a switching from a twisted internal charge transfer (TICT) to a planar internal charge transfer (PICT) state. For the protonated probes (i.e., 3B5/H+ and 4B5/H+), the fluorescing species is the localized stilbene fluorophores, but dual fluorescence is induced upon metal-ion recognition through a deprotonation process. Two compound series of trans-4-aminostilbenes DS and DCS (D-A and D-only substituted) to gain further insight into solvent effects on the photoisomerization, the temperature-dependent fluorescence lifetimes in methylcyclohexane and in acetonitrile were determined. The introduction of N-phenyl substituents to 4-aminostilbenes leads to a more stable the 1t*-state and reduced torsion barrier (Ea) in polar solvent. Although, the 1t*-state does not like 1p*-state not to be able accurately to describe, but there the molecular polarity are showen that just compared the Ea values with polar solvent and nonpolar solvent.
    Appears in Collections:[Graduate Institute of Chemistry] Electronic Thesis & Dissertation

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