Spectroscopic explorations of redox active metal-organic frameworks

氧化还原活性金属有机骨架的光谱探索

• 批准号: 2003910
• 负责人: Jenny Lockard
• 金额: $ 38.25万
• 依托单位: Rutgers University Newark
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2003910&HistoricalAwards=false
• 关键词: Spectroscopic; explorations; redox; active; metal

NON-TECHNICAL SUMMARY:This project involves the investigation of a class of porous materials called metal-organic frameworks that have potential applications ranging from fuel cell technology to industrial chemical production to solar energy conversion. While significant progress has been made in developing novel frameworks for these purposes, basic insight on how these materials work is severely lacking. The research activities in this project, which is supported by the Solid State and Materials Chemistry Program in the Division of Materials Research, rely on several X-ray and optical characterization methods to meet this need. The study targets a fundamental understanding of the properties and processes behind the applications, including how charges move and are distributed in these materials. The outcome of this work is crucial for facilitating the rational design of the next generation of these materials with improved performances and therefore has far reaching implications for a broad range of energy and environmental sustainability applications. Furthermore, as part of a broader mission to integrate research in education, the outreach component of the project provides not only hands-on research experiences for high school science teachers in the Newark region, but a mechanism for translating those experiences into meaningful high school science curricula that meet the specific needs of the students in this urban community. This outreach initiative stands to have a large impact on the students in these schools since it targets the educators that teach them. TECHNICAL SUMMARY:With this project, supported by the Solid State and Materials Chemistry Program in the Division of Materials Research, researchers focus on understanding fundamental structure/function relationships in redox and photoredox active metal organic frameworks (MOFs), an emerging class of materials composed of metal ions or clusters connected by organic molecules to form crystalline microporous networks. Their intrinsic porosity and tunable architecture allow electronic structure (bandgap-like) manipulation, selective guest species interaction and the incorporation of redox active components and other synergistic characteristics. Furthermore, these multicomponent framework functionalities inevitably lead to increasingly complicated structure-function relationships, involving subtle structural rearrangements, electronic delocalization and cooperative interactions of the framework host and guest species. Redox active MOFs therefore not only engender emerging technological interest but serve as a unique and fascinating platform for fundamental studies of host-guest chemistry, electron transfer and organometallic photophysics in 3D coordination space. The project focuses on MOF systems that exhibit redox activity in the ground state, excited state and/or associated with donor-acceptor host-guest interaction. The principal objectives in studying these systems are to expose the prevalence and role of electronic delocalization and pertinent electronic and molecular level structural changes associated with their redox or photoredox processes. To accomplish this, a targeted set of vibrational, optical, and X-ray spectroscopy methods are employed in combinations of steady state, in situ, and in some cases time-resolved studies of MOF systems to garner real time information on their electronics, host-guest interactions and molecular level structure changes. These insights help elucidate the mechanisms behind their redox behavior. Ultimately the trends afforded by this study facilitate the rational design of the next generation of MOF materials with improved performance for redox-based applications.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.

非技术摘要：该项目涉及一类称为金属有机框架的多孔材料的研究，这些材料具有从燃料电池技术到工业化学品生产到太阳能转换的潜在应用。虽然在为这些目的开发新框架方面取得了重大进展，但严重缺乏对这些材料如何工作的基本见解。该项目的研究活动由材料研究部的固态和材料化学计划支持，依靠几种X射线和光学表征方法来满足这一需求。这项研究的目标是对应用背后的特性和过程有一个基本的了解，包括电荷如何在这些材料中移动和分布。这项工作的结果对于促进下一代这些材料的合理设计具有改进的性能至关重要，因此对广泛的能源和环境可持续性应用具有深远的影响。此外，作为将研究纳入教育的更广泛使命的一部分，该项目的推广部分不仅为纽瓦克地区的高中科学教师提供了实践研究经验，而且还提供了一种机制，将这些经验转化为有意义的高中科学课程，满足这一城市社区学生的具体需求。这一外联举措将对这些学校的学生产生巨大影响，因为它针对的是教他们的教育工作者。通过该项目，由材料研究部的固态和材料化学计划支持，研究人员专注于了解氧化还原和光氧化还原活性金属有机框架（MOFs）的基本结构/功能关系，这是一类由有机分子连接的金属离子或簇组成的新兴材料，形成结晶微孔网络。它们的固有孔隙率和可调结构允许电子结构（带隙样）操纵，选择性客体物种相互作用和氧化还原活性组分和其他协同特性的掺入。此外，这些多组分的框架功能不可避免地导致越来越复杂的结构-功能关系，涉及微妙的结构重排，电子离域和合作的框架主体和客体物种的相互作用。因此，氧化还原活性MOFs不仅引起了新兴的技术兴趣，而且还为3D配位空间中的主-客体化学，电子转移和有机金属化学物理学的基础研究提供了独特而迷人的平台。该项目的重点是在基态，激发态和/或与供体-受体主体-客体相互作用相关的表现出氧化还原活性的MOF系统。研究这些系统的主要目标是揭示电子离域和相关的电子和分子水平的结构变化与它们的氧化还原或光氧化还原过程的流行和作用。为了实现这一目标，一组有针对性的振动，光学和X-射线光谱学方法的组合采用稳态，原位，并在某些情况下，时间分辨的研究MOF系统，以获得真实的时间信息，他们的电子，主客体相互作用和分子水平的结构变化。这些见解有助于阐明其氧化还原行为背后的机制。最终，这项研究提供的趋势促进了下一代MOF材料的合理设计，并提高了氧化还原应用的性能。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Local Coordination and Electronic Structure Ramifications of Guest-Dependent Spin Crossover in a Metal–Organic Framework: A Combined X-ray Absorption and Emission Spectroscopy Study

金属有机框架中客体相关自旋交叉的局域配位和电子结构后果：X 射线吸收和发射光谱联合研究

• DOI: 10.1021/acs.inorgchem.2c00774
• 发表时间: 2022
• 期刊: Inorganic Chemistry
• 影响因子: 4.6
• 作者: Solovyev, Mikhail;Kucheryavy, Pavel;Lockard, Jenny V.
• 通讯作者: Lockard, Jenny V.

High resolution x-ray emission spectrometer for multiple hard x-ray emission lines: Demonstration for Cu Kα and Kβ emissions

用于多条硬 X 射线发射谱线的高分辨率 X 射线发射光谱仪：Cu Kα 和 Kβ 发射演示

• DOI: 10.1063/5.0048726
• 发表时间: 2021
• 期刊: Review of Scientific Instruments
• 影响因子: 1.6
• 作者: Solovyev, Mikhail A.;Lockard, Jenny V.;Huang, XianRong;Heald, Steve M.;Sun, Cheng-Jun
• 通讯作者: Sun, Cheng-Jun