CAREER: Understanding and Ccontrolling Fatigue in Photo-Responsive MOFs: Characterizing Photochromic Transformations in Single Crystals

职业：理解和控制光响应 MOF 中的疲劳：表征单晶中的光致变色转变

• 批准号: 1455039
• 负责人: Jason Benedict
• 金额: $ 60万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1455039&HistoricalAwards=false
• 关键词: CAREER; Understanding; Ccontrolling; Fatigue; Photo; CAREER; Understanding; Ccontrolling; Fatigue; Photo

Non-technical Abstract:In this project funded by the Solid-State Materials Chemistry program of the Division of Materials Research, the research team is developing crystalline porous materials that are activated by UV light. The photo-active chemical groups change shape when exposed to light. These light-driven transformations cause the pores (holes) and channels of the crystalline frameworks to change shape leading to materials capable of selectively absorbing or releasing guest molecules, for example pharmaceutical drugs, but only when exposed to the proper wavelength of light. In addition to advancing our understanding of the fundamental photochemistry that occurs in these novel materials, the research establishes design principles to understand and ultimately control and prevent fatigue (failure) in a variety of photo-responsive materials. The education and outreach activities bring crystallography and X-ray science into U.S. classrooms through the continued development of an X-ray science course for advanced undergraduate and graduate students. The educational projects, including a nation-wide crystal growing competition, bring concepts of crystals and light to K-12 classrooms through the development of hands-on experiments and curricular development for teachers and students.Technical Abstract:This research focuses on identifying and understanding the root causes of fatigue in photochromic materials with the ultimate goal of developing design principles to control fatigue in any photo-responsive system. The primary objective is developing a detailed molecular level understanding of the photochemistry occurring within diarylethene-based materials, an exciting niche in the nascent field of photo-responsive metal-organic frameworks. Specific aims of the research include: (1) the synthesis and characterization of new diarylethene-based photoswitchable linkers and metal-organic frameworks prepared from these linkers, (2) quantifying the photophysics of photochromic molecules in crystalline environments using spectroscopic and diffraction methods to determine reaction energetics and limitations, (3) determining the factors and triggers that govern fatigue in these materials, (4) developing new techniques to assess the distribution of guest species within the metal-organic framework nanopores and determining their impact on the photophysical properties of the crystalline frameworks, (5) using the knowledge gained to rationally design and engineer advanced photochromic materials with enhanced properties, namely improved resistance to fatigue. The primary research tools include traditional and in situ single crystal X-ray diffraction (photo-crystallography), steady-state and time-resolved absorption spectroscopy/microscopy, nuclear magnetic resonance (NMR), mass spectrometry, thermogravimetric analysis, and computational modeling.

非技术摘要：在由材料研究部固态材料化学计划资助的该项目中，研究小组正在开发由紫外线激活的结晶多孔材料。光活性化学基团在暴露于光线时会改变形状。这些轻驱动的转换导致孔（孔）和晶体框架的通道改变形状，从而导致能够选择性吸收或释放客体分子的材料，例如药物，但仅在暴露于适当的光线时。除了促进我们对这些新型材料中发生的基本光化学的理解外，该研究还建立了设计原理，以理解并最终控制和防止各种光响应材料中的疲劳（失败）。通过为高级本科生和研究生开发X射线科学课程，教育和外展活动将晶体学和X射线科学带入了美国教室。 The educational projects, including a nation-wide crystal growing competition, bring concepts of crystals and light to K-12 classrooms through the development of hands-on experiments and curricular development for teachers and students.Technical Abstract:This research focuses on identifying and understanding the root causes of fatigue in photochromic materials with the ultimate goal of developing design principles to control fatigue in any photo-responsive system.主要目的是对基于日记甲烷的材料中发生的光化学进行详细的分子水平理解，这是光电响应性金属有机框架的新生领域中令人兴奋的利基市场。 该研究的具体目的包括：（1）从这些接头制备的新的基于二径乙烯的可连接器和金属有机框架的合成和表征，（2）使用光谱环境中的光色素分子的光学物理量化，使用光谱和衍射方法来确定反应能量和限制，以确定这些因素和限制，以下（3），以下（3 （4）开发新技术来评估金属有机框架纳米孔中客人物种的分布，并确定其对晶体框架的光物理性能的影响，（5）使用合理设计和工程师高级光有关具有增强性能的知识和工程师的高级光有关材料的知识，即增强了对疲劳的抵抗力。主要的研究工具包括传统和原位单晶X射线衍射（照片结晶），稳态和时间分辨的吸收光谱/显微镜，核磁共振（NMR），质谱，热力学分析和计算建模。