NSF-BSF: Investigating Magnetic Surfaces as a New Approach to Enantioseparations

NSF-BSF：研究磁性表面作为对映体分离的新方法

• 批准号: 1852588
• 负责人: David Waldeck
• 金额: $ 46.94万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1852588&HistoricalAwards=false
• 关键词: NSF; BSF; Investigating; Magnetic; Surfaces

Chirality, or the nonsuperimposability of mirror images, is a fundamental symmetry property of Nature. Just as human left and right hands are nonsuperimposable mirror images, biomolecules such as protein and DNA and other biologically-active molecules are chiral. The nonsuperimposable structural forms of these molecules are referred to as enantiomers. Artificially synthesized molecules are often a mixture of enantiomers. The ability to separate the mixtures into enantiomerically-pure compounds, or a single enantiomer, is particularly important to the chemical and pharmaceutical industries, as one enantiomer may have an entirely different effect than another. Yet, enantiomeric separations remain a costly aspect of the chemical production process. With support from the Molecular Separations program in the Division of Chemical, Bioengineering, Environmental, and Transport Systems, and partial co-funding from the Chemical Measurement and Imaging program in the Division of Chemistry, the PIs will examine the application of a novel and potentially generic principle for the separation of enantiomers using magnetic solid surfaces. In chiral molecules, applying a voltage affects how strongly the molecule interacts with a ferromagnetic surface. The strength of the interaction depends on whether the molecule is left-handed or right-handed. To separate enantiomers using magnetic surfaces and applied voltages, however, the chiral molecules and surface must be in direct contact. The goal of the project is to establish the molecular parameters affecting the separation and to identify the ideal magnetic materials. The ability to separate enantiomers using such an approach has the potential to reduce the cost of producing drugs and other agriculturally-relevant molecules, improving human health and promoting sustainability.The proposed activity builds on fundamental insights into the chiral induced spin selectivity effect and the recent finding that charge polarization in chiral molecules is accompanied by spin polarization. Recent results show that chiral molecules enantiospecifically adsorb on ferromagnets, where the adsorbed enantiomer is determined by the direction of magnetization of the substrate. The molecule's spin polarization affects the adsorption energy with a magnetic surface primarily through a change in the Pauli repulsion. The spin polarization changes the symmetry constraints on the electronic wavefunction, and this strongly affects the Pauli repulsion energy as the electron cloud of the molecule overlaps with the electronic wavefunctions of the substrate. Based on this behavior, a new approach to enantioselective separations and purification using magnetic materials will be developed. This goal will be accomplished through four objectives: 1) examining how the enantioselective adsorption of chiral molecules depends on the molecular properties; 2) examining different chromatographic constructs for separating mixtures of enantiomers; 3) exploring and defining the experimental conditions for efficient separations; and 4) examining the use of crystallization with magnetic surfaces for separations. The research will result in fundamental understanding of enantiomeric separations using magnetic materials.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.

手征性，或镜像的不可叠加性，是自然界的一个基本对称属性。就像人类的左手和右手是不可重叠的镜像一样，生物分子如蛋白质和DNA以及其他生物活性分子都是手性的。这些分子的不可重叠的结构形式被称为对映异构体。化学合成的分子通常是对映异构体的混合物。将混合物分离成对映体纯化合物或单一对映体的能力对于化学和制药工业特别重要，因为一种对映体可能具有与另一种完全不同的效果。然而，对映异构体分离仍然是化学生产过程中成本高昂的方面。在化学，生物工程，环境和运输系统部门的分子分离计划的支持下，以及化学部门化学测量和成像计划的部分共同资助下，PI将研究一种新的和潜在的通用原理的应用，用于使用磁性固体表面分离对映体。在手性分子中，施加电压会影响分子与铁磁表面相互作用的强度。相互作用的强度取决于分子是左手还是右手。然而，为了使用磁性表面和施加的电压分离对映体，手性分子和表面必须直接接触。该项目的目标是建立影响分离的分子参数，并确定理想的磁性材料。使用这种方法分离对映体的能力有可能降低生产药物和其他农业相关分子的成本，改善人类健康和促进可持续性。拟议的活动建立在对手性诱导的自旋选择性效应的基本见解和最近的发现，即手性分子中的电荷极化伴随着自旋极化。最近的研究结果表明，手性分子对映体特异性吸附在铁磁体上，其中吸附的对映体由基底的磁化方向决定。分子的自旋极化主要通过泡利排斥的变化影响磁性表面的吸附能。自旋极化改变了对电子波函数的对称性约束，这强烈地影响了泡利排斥能，因为分子的电子云与衬底的电子波函数重叠。基于这种行为，将开发一种新的方法，利用磁性材料的对映体选择性分离和纯化。这一目标将通过四个目标来实现：1）研究手性分子的对映选择性吸附如何取决于分子性质; 2）研究用于分离对映异构体混合物的不同色谱结构; 3）探索和定义有效分离的实验条件;以及4）研究使用磁性表面进行结晶分离。该研究将导致对使用磁性材料的对映体分离的基本理解。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

Enantiospecificity of Cysteine Adsorption on a Ferromagnetic Surface: Is It Kinetically or Thermodynamically Controlled?

• DOI: 10.1021/acs.jpclett.1c02087
• 发表时间: 2021-08-12
• 期刊: JOURNAL OF PHYSICAL CHEMISTRY LETTERS
• 影响因子: 5.7
• 作者: Lu, Y.;Bloom, B. P.;Waldeck, D. H.
• 通讯作者: Waldeck, D. H.

Spin-Dependent Enantioselective Electropolymerization

自旋依赖性对映选择性电聚合

• DOI: 10.1021/acs.jpcc.0c06238
• 发表时间: 2020
• 期刊: The Journal of Physical Chemistry C
• 作者: Tassinari, Francesco;Amsallem, Dana;Bloom, Brian P.;Lu, Yiyang;Bedi, Anjan;Waldeck, David H.;Gidron, Ori;Naaman, Ron
• 通讯作者: Naaman, Ron

The spin selectivity effect in chiral materials

• DOI: 10.1063/5.0049150
• 发表时间: 2021-04-01
• 期刊: APL MATERIALS
• 影响因子: 6.1
• 作者: Waldeck, D. H.;Naaman, R.;Paltiel, Y.
• 通讯作者: Paltiel, Y.