Ratiometry of monomer/excimer emissions of dipyrenyl calix[4]arene in aqueous media

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• 作者：Hyun Jung Kim ; Duong Tuan Quang ; Jooyeon Hong ; Guipeun Kang ; Sihyun Ham ; Jong Seung Kim
• 关键词：Calixarene ; Acridinium salts ; Acridanes ; Photoswitch
• 刊名：Tetrahedron
• 出版年：2007
• 出版时间：29 October 2007
• 年：2007
• 卷：63
• 期：44
• 页码：10788-10792
• 全文大小：541 K

文摘

Variations in the ratio of monomer/excimer emissions from pyrenyl groups bound to a calix[4]arene through facing carboxamidomethyl substituents have been investigated in H₂O/CH₃CN mixtures. Above a level of 50 % H₂O, monomer emission declines and the excimer emission concomitantly increases. DFT calculations support the argument that disruption of intramolecular NHO bonds by water results in a geometry, which favors contact of the pyrene units and thus a strong excimer emission. Addition of Fe(III) to a H₂O/CH₃CN (4:1, v/v) solution of 1 at pH 6.1 quenches both monomer and excimer emissions through electron transfer (eT) from excited pyrene to the metal ion.