CAREER: Zwitterionic Metal-Organic Frameworks with Multi-Stimulus-Responsive Properties

非技术摘要：这个CAREER项目是一个综合的研究，教育和推广计划，由材料研究部的固态和材料化学计划资助。该研究计划的总体目标是设计策略，使合成一类新的先进多孔材料组成的电荷分离的分子积木。这些电荷可以执行期望的功能以吸引材料的孔内的特定客体分子。在一项研究中，将探索光与这些电荷相互作用的能力，以触发客体分子的释放，从而确定材料是否可以再生到原始状态。该特征对于寻求气体的吸附或分离的多种环境应用特别有用，例如分别具有抵抗全球变暖的总体目标的氢存储和碳捕获。 利用研究活动是教育计划，这将使克拉克森大学提供一个更强大的，ACS批准的化学课程，为广泛，严格的化学教育，为学生提供智力，实验和沟通技能的基础，成为有效的专业人士。外展计划是动手，并结合国家的最先进的结晶仪器，以显着加强和扩大高中到大学管道的学生从农村北部国家的纽约州通过增加他们的接触和兴趣在干领域和职业。X射线衍射工作坊将为参与者提供培训，以了解和适当地利用最精确的方法来确定晶体结构，从而使基本的结构-性能relationship.Technical摘要：拟议的研究计划解决的基本问题，以多刺激响应吸附性能和快速可控释放的客体分子的功能多孔材料的进步。提出了使用两性离子金属-有机框架（ZW MOF）构建块，其分子表面显示具有可调电场梯度的良好分离的分子内电荷。这些梯度提供了潜在的多点吸附位点，其可以在MOF自组装之前在两性离子配体内以分子水平设计。一旦两性离子被引入到MOFs中，它们的电场梯度在孔内产生带电的有机表面（COS），这反过来又使客体分子吸附，从而产生限定的吸附性质。两性离子最重要的特征是它们对外部刺激（例如光或电化学）的敏感性，从而产生可切换的COS，其能够显著控制和调节吸附性质。具体办法是：（1）设计和研究ZW配体作为一种新的、简单的和可控的手段，将COS引入到孔衬中，以产生具有限定的主体-客体相互作用的M0 F;（2）探索合成后修饰反应作为将ZW官能团引入M0 F的替代途径;以及（3）通过客体分子从M0 F孔的可控释放来展示和优化COS的多刺激响应可调性。这些实验将最终提供一个强大的工具，以定制具有可调主客体相互作用的MOFs，并将产生一种新型多刺激响应材料的基础知识，该材料具有独特的吸附和解吸性能。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Non-technical Abstract:This CAREER project is an integrated research, education, and outreach program funded by the Solid-State and Materials Chemistry program of the Division of Materials Research. The overall goal of the research plan is to devise strategies that enable the synthesis of a new class of advanced porous materials composed of charge-separated molecular building blocks. These charges can perform a desired function to attract specific guest molecules within the material's pores. In one line of research, the ability of light to interact with these charges will be explored to trigger the release of guest molecules to determine if the material can be regenerated to its original state. This feature would be particularly useful for a multitude of environmental applications that seek the adsorption or separation of gases, such as hydrogen storage and carbon capture respectively with the general objective to counteract global warming. Leveraging the research activities is the educational plan that will allow Clarkson University to offer a stronger, ACS-approved chemistry program, the foundation for a broad, rigorous chemistry education that provides students with the intellectual, experimental, and communication skills to become effective professionals. The outreach program is hands-on and incorporates state-of-the-art crystallography instrumentation to significantly strengthen and expand the high school to college pipeline for students from the rural North Country of New York State by increasing their exposure to and interest in STEM fields and careers. An X-ray diffraction workshop will provide participants with the training to understand and appropriately utilize the most precise method of determining crystal structures, thus allowing the analysis of fundamental structure-property relationship.Technical Abstract:The proposed research plan addresses fundamental questions essential to the advancement of functional porous materials with multi-stimulus-responsive adsorption properties and rapid controllable release of guest molecules. Proposed is the use of zwitterionic metal-organic framework (ZW MOF) building blocks whose molecular surfaces show well-separated intramolecular charges with tunable electric field gradients. These gradients present potential multi-point adsorption sites that can be designed at a molecular level within the zwitterionic ligands prior to MOF self-assembly. Once zwitterions are incorporated into MOFs, their electric field gradients yield charged organic surfaces (COSs) within the pores, which in turn polarize guest molecules, resulting in defined adsorption properties. The most important feature of zwitterions is their sensitivity to external stimuli (e.g. light or electrochemical), resulting in switchable COSs that enable significant control and tunability of adsorption properties. Specific approaches are to: (1) Design and investigate ZW ligands as a new, simple, and controllable means to introduce COSs into pore linings to create MOFs with defined host-guest interactions; (2) Explore post-synthetic modification reactions as alternative routes for introducing ZW functionalities into MOFs; and (3) Demonstrate and optimize the multi-stimulus-responsive tunability of COSs by controllable release of guest molecules from MOF pores. These experiments will ultimately provide a powerful tool to tailor MOFs with tunable host-guest interactions and will generate fundamental knowledge on a novel type of multi-stimulus-responsive material with distinct adsorption and desorption properties.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.