Fluorescent guests hosted in fluorescent dendrimers
Fluorescent guests hosted in fluorescent dendrimers
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DOI：
10.1016/s0040-4020(01)01094-8
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发表时间：
2002-01-21
期刊：
影响因子：
2.1
通讯作者：
Vögtle, F
中科院分区：
文献类型：
--
作者：
Balzani, V;Ceroni, P;Vögtle, F
我们已经研究了形成的主-客体复合物之间的树枝状聚合物，与丹磺酰单元在外围（主机）与染料分子（客人）的聚（丙烯胺）家庭功能化。每个树枝状聚合物nD（其中代数n为1至5）在外围包含2（n+1）（即对于5D为64）个丹磺酰基官能团，在内部包含2（n+1）-2（即对于5D为62）个叔胺单元。研究得最彻底的系统是以曙红为客体的系统。结果表明：（i）溶解在二氯甲烷溶液中的nD树枝状大分子从水溶液中萃取曙红;（ii）树枝状大分子中曙红分子的最大数目随着树枝状大分子代数的增加而增加，对于5D树枝状大分子，最大可达12个;（iii）树枝状大分子的外围丹磺酰单元的荧光通过能量转移被宿主曙红分子完全猝灭;（iv）宿主曙红分子的荧光被部分淬灭;（v）曙红分子可以占据树枝状结构内部的两个不同位点（或两个基本上不同位点的家族）;（vi）树枝状聚合物中宿主曙红的激发通过曙红三重激发态引起分子氧发射的敏化。荧光素和玫瑰红的性质与曙红相似，而萘荧光素则不能提取。4D树枝状聚合物提取的染料分子的最大数目为25个，对于玫瑰红和约25个。1的荧光素，表明主-客体物种的形成有关的电子性质，而不是染料分子的大小。(C)2002爱思唯尔科技有限公司。保留所有权利。
We have investigated the formation of host-guest complexes between dendrimers, of the poly(propylene amine) family functionalized with dansyl units at the periphery (hosts) with dye molecules (guests). Each dendrimer nD, where the generation number n goes from I to 5, comprises 2(n+1) (i.e. 64 for 5D) dansyl functions in the periphery and 2(n+1)-2 (i.e. 62 for 5D) tertiary amine units in the interior. The most thoroughly investigated systems were those with eosin as a guest. The results obtained show that: (i) the nD dendrimers dissolved in dichloromethane solution extract eosin from aqueous solutions; (ii) the maximum number of eosin molecules hosted in the dendrimers increases with increasing dendrimer generation, up to a maximum of 12 for the 5D dendrimer; (iii) the fluorescence of the peripheral dansyl units of the dendrimers is completely quenched via energy transfer by the hosted eosin molecules; (iv) the fluorescence of the hosted eosin molecules is partially quenched; (v) the eosin molecules can occupy two different sites (or two families of substantially different sites) in the interior of the dendritic structure; (vi) excitation of eosin hosted in the dendrimers causes sensitization of the dioxygen emission via eosin triplet excited state. The behavior of fluorescein and rose bengal is qualitatively similar to that of eosin, whereas naphthofluorescein is not extracted. The maximum number of dye molecules extracted by the 4D dendrimer is 25 for rose bengal and ca. 1 for fluorescein, showing that the formation of host-guest species is related to the electronic properties rather than to the size of the dye molecules. (C) 2002 Elsevier Science Ltd. All rights reserved.