Refractive index dependence of the Forster resonance excitation transfer rate
Refractive index dependence of the Forster resonance excitation transfer rate
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DOI：
10.1021/jp013927
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发表时间：
2002-05-23
影响因子：
3.3
通讯作者：
van Amerongen, H
中科院分区：
文献类型：
--
作者：
Knox, RS;van Amerongen, H
共振电子激发转移的速率或产率是生物学研究的重要工具，用于估计发色团之间的距离。除了发色团间的距离，这个速率或产率取决于其他几个参数，这些参数对于确定正确的距离显然很重要。特别地，在以折射率n为特征的介质中，速率的表达式包含因子n（-4）。我们在这里认为，正确的n值是供体-受体中介介质的n值，而不是像一些人认为的那样是整个溶剂的n值。选择显然是重要的任何定量应用的理论，因为指数的典型相关材料的范围从1.3至1.6。在我们的分析中，偶极强度与辐射寿命之间的关系式需要修正。这导致了对紫色细菌天线复合物中激子离域量估计的修正（下降25%）。在我们的分析中，我们区分了折射率影响速率的三种物理上不同的方式，并建议如何处理它们。
The rate or yield of resonance electronic excitation transfer is an important tool of biological research, used to estimate distances between chromophores. Besides the interchromophore distance, this rate or yield depends on several other parameters that are clearly important for determining the correct distances. In particular, in a medium characterized by a refractive index n, the expression for the rate contains a factor n(-4). We argue here that the correct value for n is that of the donor-acceptor intervening medium, not that of the overall solvent, as has been argued by some. The choice is clearly important to any quantitative application of the theory since the index of typical relevant materials ranges from 1.3 to 1.6. Incidental to our analysis, a certain expression that connects dipole strengths with radiative lifetimes requires correction. This leads to revisions of estimates of the amounts of exciton delocalization in antenna complexes from purple bacteria (downward by 25%). In our analysis we distinguish three physically distinct ways in which refractive index affects the rate and suggest how they should be handled.