Artificial Light Harvesting Arrays

在这项研究计划中，将构建具有光活性的分子自组装阵列，并将模仿自然捕光复合体的一些基本特征。卟啉发色团将被组装成天线，以促进卟啉分子之间的能量转移，并随后将能量转移到陷阱，在那里可以启动化学反应。每个天线将通过自发自结合，通过杂环的多点氢键组装，这些杂环是共价键合到卟啉环上的。一个、两个或四个这样的杂环将被键合到一个卟啉环上，从而产生二聚体、多分子带、环状单体和三维超分子阵列。这样，无论是在溶液中，还是在介晶相中或在固态中，都会形成高度定向的结构，每个结构都有离散的卟啉发色团，位于激发能量迁移和转移的临界距离内。来自有机动力学项目的这笔资金支持德克萨斯大学奥斯汀分校的安东尼·M·哈里曼博士的研究。植物获取光能以合成分子，其中叶绿素是能量获取系统，这显然是重要的。在自然界中，这是一个复杂的过程，一系列的叶绿素分子被组装起来，以完成收集光线的任务。叶绿素的卟啉环部分是光吸收单位。在这个项目中，将自组装卟啉环，并研究从卟啉环到附加的能量捕获部分的光能转移。该系统将用于模拟自然光采集系统。

In this research program, self-assembling arrays of molecules will be constructed that are photoactive and will mimic some of the essential features of natural light harvesting complexes. Porphyrin chromophores will be assembled so as to form antennae that facilitate energy migration between porphyrin molecules and subsequent energy transfer to a trap, where a chemical reaction can be initiated. Each antenna will be assembled by spontaneous self-association, by multi-point hydrogen bonding of heterocycles that are covalently bonded to the porphyrin ring. One, two, or four such heterocycles will be bonded to a single porphyrin ring such that dimers, polymolecular ribbons, cyclomers, and three- dimensional supramolecular arrays will result. In this manner, highly oriented structures will be formed in solution, in a mesophoric phase, or in the solid state, each of which has discrete porphyrin chromophores positioned within the critical distance for excitation energy migration and transfer. %%% This grant from the Organic Dynamics Program supports the research of Dr. Anthony M. Harriman at the University of Texas, Austin. The harvesting of light energy for the synthesis of molecules by plants, whereby chlorophyll is the energy harvesting system, is of obvious importance. This is a complex process in nature, where an array of chlorophyll molecules are assembled for the task of light harvesting. The porphyrin ring portion of chlorophyll is the light absorbing unit. In this project, porphyrin rings will be self-assembled and the transfer of light energy from the porphyrin ring to an appended energy trapping moiety will be studied. This system will serve to mimic the natural light harvesting system.