二苯乙烯吡啶衍生物及其金屬錯合物之光物理、光化學性質及其與陽離子作用變化之研究

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2009

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本論文利用Wittig reaction合成出具有反式二苯乙烯的吡啶衍生物,並在反式二苯乙烯其中一苯環4號位置接上不同的推電子基(二苯胺、單氮冠醚)而造成強烈分子內電荷轉移,利用此一特性我們討論這系列衍生物的光物理、光化學以及與陽離子的變化。 光物理性質部分,我們利用溶劑效應來觀察不同分子內電荷轉移的效率,發現推電子能力:二苯胺略大於單氮冠醚大於氫原子,拉電子能力:三吡啶衍生物略大於二吡啶衍生物;且由比較不同溶液中的kr與knr值我們推測具有二苯胺與單氮冠醚的反式二苯乙烯衍生物在高極性溶液中會產生TICT(Twisted Internal Charge Transfer)以至於有反能隙理論(anti-energy gap law)的現象發生。 光化學性質部分,利用照光反應研究二苯乙烯分子的順反異構化與不同取代基或溶液極性對於此異構化的影響,結果合乎胺基共軛效應(amino-conjudgate effect),並發現這一系列的分子(具有TICT現象)異構化行為並不明顯 另外與陽離子的作用我們可以觀察到大部分陽離子皆與吡啶衍生物靠近,只有銀離子可與冠醚端作用,而汞離子與鉻離子則是先與吡啶端作用後下一當量再與冠醚作用。
A new series of stilbene containing 2,2’:6’,2”-terpyridine or 6-phenyl-2,2'-bipyridine ligands has been synthesized. In order to enhance the internal charge transfer (ICT), we introduced different electron-donating subsituents such as triphenylamine and thioaza-crown. According to the results from solvent dependent studies, both L4、L4’、L5 and L5’ exhibited larger Stokes shift than L3 and L3’, We also found this series of molecular exihibits anti-energy gap law, indicating a possibile twisted internal charge transfer (TICT) for moleculers with electron donating groups. Moreover, the reduced isomerization behavor in moleculers with diphenylamine and thioaza-crown is attributed to the “ amino-conjugation effect ”. The solvent effect of this series of organic moleculers coordinating with Pt(II) was different from organic ones, we found an additional band at higher wavelength in non-polar solvent and assign this emission originated from 3MLCT. The solution absoption spectrum of these mloeculers shifted when we added different cation,according to the shift we can presume cation coordinate to whitch side of the moleculers.

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冠醚, 分子辨識, 反式二苯乙烯, crown-ether, molecular sensor, trans-stilbene

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