Interaction of Pheophorbide a molecules covalently linked to DAB dendrimers
Interaction of Pheophorbide a molecules covalently linked to DAB dendrimers
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DOI：
10.1016/j.optcom.2004.11.088
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发表时间：
2005-04-01
影响因子：
2.4
通讯作者：
Röder, B
中科院分区：
文献类型：
--
作者：
Hackbarth, S;Ermilov, EA;Röder, B
从第一代到第四代的DAB-树枝状聚合物以及二氨基己烷-全部被最大可实现量的脱镁叶绿酸a（Pheo）分子取代的化学物理性质与Pheo在乙醇溶液中的化学物理性质进行比较。树枝状聚合物表面上连接的染料分子的高局部浓度产生每个复合物内的发色团之间的相互作用。这些相互作用的调查是本文的目的。据发现，在一个树枝状聚合物-染料-复合物中的大量发色团增加了Pheo部分的堆叠概率，伴随着激子相互作用，导致激发后的快速非辐射失活。失活的效率取决于发色团彼此之间的相对位置。由于Pheo分子之间能量转移的福斯特半径大于整个复合物的直径，因此复合物内的发色团之间的能量跳跃非常迅速。仅一对激子相互作用的发色团就可以作为整个复合物的能量陷阱。(c)2004 Elsevier B. V.保留所有权利。
The photophysical properties of DAB-dendrimers from first to fourth generation as well as Diaminohexane - all substituted with the in maximum achievable quantity of Pheophorbide a (Pheo) molecules are compared with those of Pheo in ethanolic solution. The high local concentration of the linked dye molecules on the dendrimer surface yields in interactions between the chromophores within each complex. The investigation of these interactions is the aim of this paper. It was found, that a larger number of chromophores in one dendrimer-dye-complex increases the stacking probability of Pheo moieties accompanied by excitonic interaction leading to a fast non-radiative deactivation after excitation. The efficiency of deactivation depends on the relative position of the chromophores one to each other. Since the Forster radius for energy transfer between Pheo molecules is bigger than the diameter of the whole complex, energy is jumping very rapidly between the chromophores within the complex. Just one pair of excitonic interacting chromophores can act as energy trap for the whole complex. (c) 2004 Elsevier B.V. All rights reserved.