A density functional normal mode calculation of a bacteriochlorophyll a derivative
A density functional normal mode calculation of a bacteriochlorophyll a derivative
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DOI：
10.1021/ja993849s
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发表时间：
2000-04-12
影响因子：
15
通讯作者：
Marchi, M
中科院分区：
文献类型：
--
作者：
Ceccarelli, M;Lutz, M;Marchi, M
叶绿素在原核生物和真核生物的光合作用中起着重要的作用。由于它们的电子光谱对从近UV到近IR的光的收集的特定适应，它们构成了其潜在蛋白质环境的结构组织的优异的共振拉曼（RR）探针。光合膜蛋白的RR光谱提供的本地和详细的信息是显着的补充，所提供的X射线晶体学。[1]要解释细菌叶绿素RR谱的变化与其结构和局部环境的关系，需要对所观察到的拉曼谱带的振动起源有详细的了解。这些方法的结果之一是与卟啉和细菌叶绿素中的次甲基桥相关的环伸展的显著不同的行为。2在这篇文章中，我们提出了第一个高质量的DFT从头计算的振动结构的细菌叶绿素衍生物，并讨论了分配的面内频率可检测的RR光谱。
Chlorophylls play a fundamental role in procaryotic and eucaryotic photosynthesis. Because of the specific adaptation of their electronic spectra to collection of light from near UV to near-IR, they constitute excellent resonance Raman (RR) probes of the structural organization of their underlying protein environment. The local and detailed information provided by RR spectroscopy of photosynthetic membrane proteins is remarkably complementary to that provided by X-ray crystallography. 1 The interpretation of changes in the RR spectra of the bacteriochlorophylls in terms of changes of their structure and local environment requires detailed knowledge of the vibrational origins of the observed Raman bands.In the past, empirical and semiempirical approaches have been used to obtain a normal mode description of bacteriochlorophylls. One of the results of these approaches is the remarkably different behavior of the ring stretches associated with the methine bridges in porphyrins and bacteriochlorophylls. 2 In this contribution we present the first high quality DFT ab initio calculation of the vibrational structure of a bacteriochlorophyll derivative and discuss the assignment of the in-plane frequencies detectable by RR spectroscopy.