Structural characteristics that make chlorophylls green: interplay of hydrocarbon skeleton and substituents
Structural characteristics that make chlorophylls green: interplay of hydrocarbon skeleton and substituents
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DOI：
10.1039/c0nj00652a
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发表时间：
2011-01-01
影响因子：
3.3
通讯作者：
Lindsey, Jonathan S.
中科院分区：
文献类型：
--
作者：
Mass, Olga;Taniguchi, Masahiko;Lindsey, Jonathan S.
了解取代基对天然光合色素的影响对于深入理解为什么这些色素在进化过程中被选择用于光合系统至关重要。这些知识应该提供一个更周到的设计人工捕光系统。所有叶绿素的碳氢骨架都是佛宾，除了二氢卟酚特有的还原吡咯环外，还含有一个环状的五元（等环）环。合成了一个佛宾和一个13（1）-氧代佛宾（在异环中带有一个氧代基团）作为基础光谱和电子物理研究的基准分子。佛宾和13（1）-氧代佛宾大环化合物除了在还原环中的偕二甲基之外缺乏外围取代基以稳定二氢卟酚发色团。锌或游离碱13（1）-氧代叶绿酸的光谱性质和电子结构与叶绿素a的相应类似物非常相似。因此，叶绿素的基本电子性质主要是13（1）-氧代磷碱大环化合物的结果。
Understanding the effects of substituents on natural photosynthetic pigments is essential for gaining a deep understanding of why such pigments were selected over the course of evolution for use in photosynthetic systems. This knowledge should provide for a more thoughtful design of artificial light-harvesting systems. The hydrocarbon skeleton of all chlorophylls is phorbine, which contains an annulated five-membered (isocyclic) ring in addition to the reduced pyrrole ring characteristic of chlorins. A phorbine and a 13(1)-oxophorbine (which bears an oxo group in the isocyclic ring) were synthesized as benchmark molecules for fundamental spectral and photophysical studies. The phorbine and 13(1)-oxophorbine macrocycles lack peripheral substituents other than a geminal dimethyl group in the reduced ring to stabilize the chlorin chromophore. The spectral properties and electronic structure of the zinc or free base 13(1)-oxophorbine closely resemble those of the corresponding analogues of chlorophyll a. Accordingly, the fundamental electronic properties of chlorophylls are primarily a consequence of the 13(1)-oxophorbine base macrocycle.