SusChEM: Design Principles Inspired by Symmetry for Controlling Singlet Fission in Structurally Well-Defined Covalent Dimers

SusChEM：受对称性启发的设计原理，用于控制结构明确的共价二聚体中的单线态裂变

• 批准号: 1665375
• 负责人: Niels Damrauer
• 金额: $ 48万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1665375&HistoricalAwards=false
• 关键词: SusChEM; Design; Principles; Inspired; Symmetry

In this project funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professors Niels H. Damrauer and Tarek Sammakia of the Department of Chemistry and Biochemistry at the University of Colorado Boulder are synthesizing new organic molecular systems that contain two chromophores (i.e., parts of the molecules that can absorb light) and using spectroscopy to explore their photophysics. The goal is to develop design rules for how the arrangement of the chromophores controls excited state reactivity following visible light photoexcitation. The particular reaction of interest is important in certain next-generation strategies to increase the efficiency of solar cells by limiting waste heat production that generally occurs when higher energy solar photons are absorbed. This proposal establishes a fundamental research program where students are exposed to a considerable breadth of ideas in synthesis, spectroscopy, and applications of electronic structure theory. A specific outreach effort in collaboration with local high school teachers is part of the funded work that aims to provide sophisticated but affordable spectroscopic tools and curriculum ideas to Colorado high school science programs. Singlet fission is a photophysical phenomenon observed in certain organic materials wherein light absorption produces a spin-allowed singlet excited state that then non-radiatively converts to a pair of triplet excitations. If these triplets can be further transformed to charge carriers, it is possible to envision device scenarios where the solar spectrum is more efficiently utilized compared to devices in operation today. This research is predicated on the idea that molecular dimers are the fundamental unit for singlet fission and that they can provide a platform wherein synthetic manipulations that control the spatial juxtaposition and covalent interaction of chromophores are called upon to affect key photophysical rate constants. The most important design opportunity that is being tested relates to dimer point group symmetry and the idea that it can control the interference (constructive vs. destructive) of pathways in the quantum mechanical description of diabatic coupling for singlet fission. Other strategies will call on substituents to affect the relative energy of charge transfer states.

在这个由化学系化学结构、动力学和机制 B 项目资助的项目中，科罗拉多大学博尔德分校化学与生物化学系的 Niels H. Damrauer 和 Tarek Sammakia 教授正在合成包含两个发色团的新有机分子系统（即可以吸收光的分子部分）并使用光谱学来探索其光物理学。目标是制定生色团的排列如何控制可见光光激发后激发态反应性的设计规则。在某些下一代策略中，感兴趣的特定反应非常重要，通过限制通常在吸收更高能量的太阳光子时发生的废热产生来提高太阳能电池的效率。该提案建立了一个基础研究项目，让学生接触到电子结构理论的合成、光谱学和应用方面的广泛思想。与当地高中教师合作的具体外展工作是资助工作的一部分，旨在为科罗拉多州高中科学项目提供复杂但负担得起的光谱工具和课程理念。单线态裂变是在某些有机材料中观察到的光物理现象，其中光吸收产生自旋允许的单线态激发态，然后非辐射地转换为一对三线态激发。如果这些三元组可以进一步转化为电荷载流子，那么与当今运行的设备相比，可以设想更有效地利用太阳光谱的设备场景。这项研究的基础是分子二聚体是单线态裂变的基本单位，并且它们可以提供一个平台，其中需要控制发色团的空间并置和共价相互作用的合成操作来影响关键的光物理速率常数。正在测试的最重要的设计机会涉及二聚体点群对称性，以及它可以控制单线态裂变非绝热耦合的量子力学描述中路径的干扰（建设性与破坏性）的想法。其他策略将要求取代基影响电荷转移态的相对能量。

项目成果

Modular Synthesis of Rigid Polyacene Dimers for Singlet Fission

用于单线态裂变的刚性多并苯二聚体的模块化合成

• DOI: 10.1021/acs.orglett.7b03817
• 发表时间: 2018-01
• 期刊: Organic Letters
• 影响因子: 5.2
• 作者: Carey, Thomas J.;Miller, Ethan G.;Gilligan, Alexander T.;Sammakia, Tarek;Damrauer, Niels H.
• 通讯作者: Damrauer, Niels H.

Using Structurally Well-Defined Norbornyl-Bridged Acene Dimers to Map a Mechanistic Landscape for Correlated Triplet Formation in Singlet Fission

使用结构明确的降冰片基桥并苯二聚体绘制单线态裂变中相关三线态形成的机制图谱

• DOI: 10.1021/jacs.9b00904
• 发表时间: 2019-03
• 期刊: Journal of the American Chemical Society
• 影响因子: 15
• 作者: Gilligan, Alexander T.;Miller, Ethan G.;Sammakia, Tarek;Damrauer, Niels H.
• 通讯作者: Damrauer, Niels H.

Solvent-Controlled Branching of Localized versus Delocalized Singlet Exciton States and Equilibration with Charge Transfer in a Structurally Well-Defined Tetracene Dimer

结构明确的并四苯二聚体中局域与离域单线态激子态的溶剂控制分支以及电荷转移平衡

• DOI: 10.1021/acs.jpca.7b09458
• 发表时间: 2017-12
• 期刊: The Journal of Physical Chemistry A
• 作者: Cook, Jasper D.;Carey, Thomas J.;Arias, Dylan H.;Johnson, Justin C.;Damrauer, Niels H.
• 通讯作者: Damrauer, Niels H.

Triplet-Fusion Upconversion Using a Rigid Tetracene Homodimer

使用刚性并四苯同二聚体进行三重态融合上转换

• DOI: 10.1021/acs.jpclett.9b03115
• 发表时间: 2019-11
• 期刊: The Journal of Physical Chemistry Letters
• 作者: Imperiale, Christian J.;Green, Philippe B.;Miller, Ethan G.;Damrauer, Niels H.;Wilson, Mark W.
• 通讯作者: Wilson, Mark W.