Reversible Anion and Ion-Pair Recognition under Electronic Control

电子控制下的可逆阴离子和离子对识别

• 批准号: 1660329
• 负责人: Sourav Saha
• 金额: $ 32.64万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-09 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1660329&HistoricalAwards=false
• 关键词: Reversible; Anion; Ion; Pair; Recognition

With this award, the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry is funding Professor Sourav Saha of Florida State University to develop new strategies and receptors that can not only discriminate anions on the basis of their electronic properties, but also capture and release the target anions in a reversible fashion under the influence of electrons and light. Anions and cations are ubiquitous, and have diverse structures, properties, and functions. Some play important roles in biological, chemical, industrial, and environmental processes, while others are toxic and pollutants. For these reasons, it is important to regulate these charged species with high precision and selectivity. Selective ion receptors can provide scientists with systems that are recyclable, reusable, and better suited for applications in environmental protection. The graduate, undergraduate, and postdoctoral researchers working on this project will gain an array of scientific knowledge and technical expertise, from synthesis to molecular recognition. Integrated outreach activities are directed at local schools, the public library, and at students from Florida Agricultural and Mining University, an HBCU institution. Through these efforts, Dr. Saha plans to engage young and underrepresented students in hands-on experiments to motivate them to consider the pursuit of careers in science. The goal of this research is to develop new strategies to (i) discriminate anions on the basis of their electronic properties, (ii) capture anions and cations simultaneously in a cooperative fashion, and (iii) bind and release ionic guests in a reversible fashion under the influence of electrons and light. To discriminate anions in aprotic solvents, the Saha research team is exploiting the ability of ð-acidic naphthalenediimide (NDI) receptors to accept electron(s) from strong Lewis basic anions, form charge-transfer complexes with less basic anions, and engage in anion?ð and CH···anion interactions with charge-diffuse anions. To overcome the ion-pairing effect that weakens the binding interactions between ionic guests and receptors, tweezers-shaped, ditopic ion-pair receptors are being developed by tethering two terminal NDI units with folded linkers that can bind cations. The hypothesis is that cation binding at the linker units should facilitate anion binding between the two overlapping NDI units and vice versa. During biphasic extractions, these ditopic receptors should selectively extract salts that contain less hydrated charge-diffuse anions from aqueous to organic medium, while the more hydrated hard anions should remain in water. NDI-based cationic metallacycles are being constructed to capture large charge-diffuse anions inside their cavities through anion/NDI interactions. The metal ion corners should mitigate the ion-pairing effects. The reversible redox chemistry of the NDI units and the tendency of their reduced forms to expel anions offer a new approach to release the captured anions from these receptors upon chemical, electrochemical, and/or photochemical reduction.

凭借该奖项，化学系的高分子、超分子和纳米化学项目正在资助佛罗里达州立大学的 Sourav Saha 教授开发新的策略和受体，不仅可以根据阴离子的电子特性来区分阴离子，还可以捕获和释放阴离子阴离子和阳离子在电子和光的影响下以可逆的方式存在，并且具有不同的结构、性质和功能。由于这些原因，以高精度和选择性调节这些带电物质可以为科学家提供可回收、可重复使用且更适合的系统。从事该项目的研究生、本科生和博士后研究人员将获得从合成到分子识别的一系列科学知识和技术专业知识。佛罗里达农业的学生通过这些努力，萨哈博士计划让年轻和代表性不足的学生参与实践实验，以激励他们考虑追求科学事业。这项研究的目标是制定新的策略，以实现科学发展。 (i) 根据电子特性区分阴离子，(ii) 以协作方式同时捕获阴离子和阳离子，以及 (iii) 在电子和光的影响下以可逆方式结合和释放离子客体以区分阴离子。在在非质子溶剂中，Saha 研究小组正在利用 ð-酸性萘二亚胺 (NDI) 受体接受来自强路易斯碱性阴离子的电子，与较少碱性阴离子形成电荷转移复合物，并参与阴离子?ð 和 CH 的能力···阴离子与电荷扩散阴离子的相互作用，克服削弱离子客体与受体之间结合相互作用的离子配对效应，镊子状，双位离子对受体是通过将两个末端 NDI 单元与可以结合阳离子的折叠接头连接起来而开发的。假设是，接头单元处的阳离子结合应促进两个重叠 NDI 单元之间的阴离子结合，反之亦然。这些双位受体应选择性地从水介质到有机介质中提取含有较少水合电荷扩散阴离子的盐，而较多水合硬阴离子应保留在正在构建基于 NDI 的阳离子金属环，以通过阴离子/NDI 相互作用捕获空腔内的大量电荷扩散阴离子，从而减轻 NDI 单元的离子配对效应和趋势。它们以还原形式排出阴离子，提供了一种通过化学、电化学和/或光化学还原从这些受体释放捕获的阴离子的新方法。

项目成果

Anion-Induced Electron Transfer

• DOI: 10.1021/acs.accounts.8b00197
• 发表时间: 2018-09-01
• 期刊: ACCOUNTS OF CHEMICAL RESEARCH
• 影响因子: 18.3
• 作者: Saha, Sourav

Anion/Naphthalenediimide Interactions in a Pd(II)-Based Tetrameric Metallocycle

• DOI: 10.1021/acs.cgd.9b00874
• 发表时间: 2019-09
• 期刊: Crystal Growth & Design
• 影响因子: 3.8
• 作者: M. A. Gordillo;P. A. Benavides;S. Saha

Pt(ii)-coordinated tricomponent self-assemblies of tetrapyridyl porphyrin and dicarboxylate ligands: are they 3D prisms or 2D bow-ties?

• DOI: 10.1039/d1sc06533e
• 发表时间: 2022-04-06
• 期刊: Chemical science
• 影响因子: 8.4
• 作者: Benavides PA;Gordillo MA;Yadav A;Joaqui-Joaqui MA;Saha S
• 通讯作者: Saha S