CAS: Exploring Multiexciton Dynamics for Triplet Upconversion in Structurally Well-Defined Covalent Dimers

CAS：探索结构明确的共价二聚体中三重态上转换的多激子动力学

• 批准号: 2102713
• 负责人: Niels Damrauer
• 金额: $ 51万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2102713&HistoricalAwards=false
• 关键词: CAS; Exploring; Multiexciton; Dynamics; Triplet

In this project, funded by the Chemical Structure, Dynamics & Mechanism B Program of the NSF Division of Chemistry, Niels Damrauer and Tarek Sammakia of the Department of Chemistry at the University of Colorado Boulder are working to gain a greater understanding of a process called “triplet upconversion” (TUC). When molecules absorb light, they are excited into a higher energy state and in TUC, the energy of two excited molecules fuses into a single excited state that is more energetic and has greater reactive potential. TUC photophysics is robust and applicable to a remarkable breadth of chemical, technological, and biological applications including solar energy conversion, chemical catalysis, light-promoted polymerization, and biological imaging. This project marshals a program that joins spectroscopy, chemical synthesis, and theory to consider fundamental aspects of this process. The understanding gained in this research will push the next-generation of molecules and materials to new levels in their ability to manipulate light energy obtained through absorption. The research team will also engage in scientific outreach at the high school level through an established relationship with the DSST schools in the Denver metropolitan area. This is a remarkable STEM-based school system with a 100% college acceptance rate for high school graduates amongst a total population that is 71% economically challenged and overwhelmingly racially diverse. Through an online synchronous platform in response to the COVID crisis, the team offer an 8-week elective to explore spectroscopy and photophysics using highly accessible 3D-printed parts, a few other inexpensive components, and a cell phone camera. This project centers around the ideas of excited state dynamical control. In the vast majority of TUC systems, monomer chromophores are used, and collisions or non-diffusional monomer/monomer encounters are called upon to negotiate all triplet fusion events. This results in very little control of the multiexciton dynamics that are critical contributors to overall yield. Matters are challenged because spin statistics are in play and because the singlet channel required for TUC is the smallest in its statistical weight. In this project, the team plans to fundamentally alter, and interrogate, the number and types of multi-exciton pathways that may contribute to successful TUC using structurally well-defined dimer systems. The team believes that the structural definition of their systems in concert with the control they maintain in manipulating physiochemical properties – such as excited state reaction driving force, excited state couplings, interchromophore spin coupling magnitudes, molecular size, and solubility – will potentially allow them to assess TUC efficiency gains achieved by exploiting intramolecular multiexciton dynamics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在该项目中，由NSF化学司的化学结构，动力学和机制B计划资助，科罗拉多博尔德大学化学系的Niels Damrauer和Tarek Sammakia正在努力获得对称为“ Triplet Upconversion”（TUC）的过程的更深入的了解。当分子吸收光时，它们会激发到较高的能量状态和TUC中，两个激发分子的能量融合到一个更伟大且具有更大活力的单个激发态。 TUC光体物理学是可靠的，并且适用于化学，技术和生物学应用的显着广度，包括太阳能转化，化学催化，光促进聚合和生物成像。该项目将一项与光谱，化学综合和理论相结合的计划，以考虑此过程的基本方面。这项研究所获得的理解将使分子和材料的下一代发展到新的水平，以操纵通过滥用获得的光能量。研究团队还将通过与丹佛都会区的DSST学校建立关系，在高中进行科学宣传。这是一个非凡的基于STEM的学校系统，在总人口中，高中毕业生的大学接受率为100％，经济挑战为71％，并且在绝对现实的潜水员中。通过在线同步平台响应COVID危机，该团队提供了为期8周的选修课，以使用高度可访问的3D打印零件，其他一些廉价的组件和手机摄像头探索光谱和摄影。该项目围绕激发状态动力控制的思想。在绝大多数TUC系统中，都使用单体发色团，并要求碰撞或非扩散单体/单体相遇来协商所有三重态融合事件。这几乎无法控制多智能动力学，这是造成整体产量的关键因素。问题之所以挑战，是因为旋转统计数据正在发挥作用，并且因为TUC所需的单线通道是其统计重量最小的。在这个项目中，团队计划从根本上更改和询问，使用结构明确定义的二聚体系统可以成功地取得成功的TUC的多exciton途径的数量和类型。该团队认为，他们的系统的结构定义与他们在操纵生理化学特性中保持的控制权一致，例如激发的状态反应驱动力，激发的状态耦合，肉鸡间旋转耦合量的幅度，分子尺寸和溶解度 - 可以通过授予Intemains nitysie notie nymolector nysiexcitriency notimentimentimentimentimeysfornity Insploinity Dynroments Insploine intamolieiexciToins intainsie intamol ofdynie theics intamol saterie totrys。并使用基金会的智力优点和更广泛的影响审查标准通过评估来诚实地获得支持。