CAREER: Framework Topology Dependent Photophysical Properties of Chromophore Assemblies within Metal-Organic Frameworks

在这个职业项目中，由化学系化学结构、动力学和机制-B计划资助，南伊利诺伊大学卡本代尔大学化学与生物化学系的Pravas Deria教授正在开发在特定结构(称为金属-有机骨架)中精心排列的高度有色有机分子的组件。当它们与光反应时，这些金属有机骨架具有独特的性质。这项研究的目标是制造具有捕捉和具体引导光的能力的骨架组合物，以有效地收集光并将其转化为存储的化学能。通过这项职业研究获得的知识将通过增强年轻学生(高中及以下)对基础科学的认识，在伊利诺伊州南部产生广泛的影响。Deria教授将招募地区高中(HS)的学生参加为期两周的化学研究夏令营，在那里他们将被介绍给基础科学研究--包括实践令人兴奋的现代仪器。中学生将在当地的一个科学中心参与演示分子色素在生物学中的“颜色科学”。这些教育项目将提供第一手经验，激励学生选择科学职业。该项目位于无机化学、有机化学和物理化学的交界处，非常适合各级科学家的教育，因为该项目将应用于太阳能、燃料和清洁能源技术。在人工化学组件中实现类似光系统II的光物理行为以有效地收集光子能量是一个挑战，因为要求进行超分子合成设计。精确和可控的颜料组织是获得功能不同于简单发色团聚集体的新组合物的先决条件。多孔晶体金属-有机骨架(MOF)提供了独特的平台来开发定义良好、溶液稳定的具有高效光子能量转换功能的分子发色团组件。然而，在定义明确的MOF中设计和控制理想的类似光系统II的光物理行为还处于早期发现阶段。控制激子形成、远程激子传播和引导激子分裂为产生功的电荷的基本规则需要完全建立在这些合成框架组件中。这一职业项目探索了作为骨架拓扑的函数来控制激子结构和动力学的新型MOF组合物，并阐明了生色团的电子结构和激发态对称性如何影响激子的离域和迁移。这项研究可能会揭示调节单重态-三重态系统间跨越量子产额的关键因素。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In this CAREER project, funded by the Chemical Structure, Dynamics, & Mechanisms-B Program of the Chemistry Division, Professor Pravas Deria of the Department of Chemistry & Biochemistry at Southern Illinois University Carbondale is developing assemblies of highly colored organic molecules carefully arranged in specific structures (known as metal-organic frameworks). These Metal-organic frameworks have unique properties when they react with light. The goal of this research is to make framework compositions with the ability to capture and specifically channel light for efficient light harvesting and conversion into stored chemical energy. The knowledge gained through this CAREER research will have a broad impact in southern Illinois by augmenting young student's (high school and below) perception towards basic science. Professor Deria will recruit regional high school (HS) students into a two-week chemistry research camp, where they will be introduced to fundamental scientific research --including hands-on experience with exciting modern instrumentation. Middle school students will be involved in demonstration of the 'Science of Colors' with molecular pigments in biology at a local Science Center. These educational programs will provide firsthand experience to inspire students to choose science careers. The project lies at the interface of inorganic, organic, and physical chemistry, and is well suited for the education of scientists at all levels as the project has applications to solar to fuels, clean energy technologies. Achieving photosystem II-like photophysical behavior for efficient photonic energy harvesting in artificial chemical assemblies is a challenge due to demanding supramolecular synthetic designs. Precise and controllable organization of pigments is a prerequisite to achieving new compositions that function differently than simple chromophore aggregates. Porous crystalline metal-organic frameworks (MOFs) offer unique platforms to develop well-defined, solution-stable molecular chromophore assemblies with efficient photon energy transducing functionality. However, the design and control of desirable photosystem II-like photophysical behavior in well-defined MOFs is at an early stage of discovery. Basic rules governing exciton formation, long-range exciton propagation, and directing exciton splitting into work-producing charges within these synthetic framework-assemblies need to be fully established. This CAREER project explores novel MOF compositions that control excitonic structure and dynamics as a function of framework topology and elucidates how chromophore electronic structure and excited-state symmetry impacts exciton delocalization and migration. The research may unveil the critical factors that modulate singlet-triplet intersystem crossing quantum yields.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.