U.S.-Greece Dissertation Enhancement: Mössbauer Spectroscopic Studies of Redox-Active Fe4O4-Cubanes

美国-希腊论文增强：氧化还原活性 Fe4O4-古巴烷的穆斯堡尔光谱研究

• 批准号: 0827841
• 负责人: Raphael Raptis
• 金额: $ 1.11万
• 依托单位: University of Puerto Rico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0827841&HistoricalAwards=false
• 关键词: U.S.; Greece; Dissertation; Enhancement; ssbauer

NSF-0827841U.S.-Greece Dissertation Enhancement: Mössbauer Spectroscopic Studies of Redox-Active Fe4O4 Cubanes ABSTRACTThis project will send Dalice M. Piñero, a student from the University of Puerto Rico at Río Piedras, to the Institute of Materials Science, NCSR ?Demokritos?, Athens, Greece, for two one-month periods to conduct 57Fe Mössbauer Spectroscopy experiments as part of her doctoral dissertation work on oligonuclear iron pyrazolato complexes. Mrs. Piñero will work with Dr. Yiannis Sanakis, an active collaborator of Dr. Raphael Raptis, the PI on this award and Mrs. Piñero?s Thesis advisor at the University of Puerto Rico. The project proposes the use Mössbauer spectroscopy to study the redox-active Fe4O4-cubane contained within the core of [Fe8O4(4-R-pz)12X4]0/n- (R = H, Cl, Br, Me, Ph; X= Cl-, Br-, SCN-, N3-) over a range of redox-modified oxidation states; five oxidation states are electrochemically accessible in these systems, from [FeIII8] to [FeIII4FeII4]. Mössbauer spectroscopy allows the differentiation between the two structurally distinct Fe-sites present in these octanuclear complexes, as well as the differentiation between oxidation states. The possible existence of Fe4O4 cubanes at the electron transfer sites of proteins has been suggested resently. Results obtained in this project will (1) contribute to the creation of a spectroscopic ?fingerprint? data bank to be used for recognition of these motifs in Nature, (2) will serve to study their electronic states with regard to localized/delocalized nature of mixed valence states, and (3) by the application of external magnetic fields, will probe the magnetic states at each oxidation state, accessed by redox modification of the all-ferric compounds. The Intellectual Merit of the project consists of the systematic study of a rare, stepwise redox-modified multi-iron cluster. The international experience to be gained by an under-represented minority student during this project and the training in techniques not available locally constitute the Broader Impacts of this project.

NSF-0827841美国-希腊学位论文增强：氧化还原活性Fe_4O_4古巴烷的穆斯堡尔谱学研究。皮涅罗，一个来自里奥皮德拉斯的波多黎各大学的学生，到材料科学研究所，NCSR？德莫克里托斯？希腊雅典，为期两个月，进行57 Fe穆斯堡尔谱实验，作为她关于寡核铁吡唑配合物的博士论文工作的一部分。 Piñero夫人将与Yiannis Sanakis博士合作，他是Raphael Raptis博士的积极合作者，该奖项的PI和Piñero夫人？他是波多黎各大学的论文导师。 该项目建议使用穆斯堡尔谱学来研究[Fe 8 O 4（4-R-pz）12 X4]0/n-（R = H，Cl，Br，Me，Ph; X= Cl-，Br-，SCN-，N3-）核心中含有的氧化还原活性的Fe 4 O 4-立方烷在一系列氧化还原修饰的氧化态下;在这些系统中，从[FeIII 8]到[FeIII 4FeII 4]，有五种氧化态是电化学可访问的。 穆斯堡尔谱允许区分存在于这些八核配合物中的两个结构不同的Fe-位点，以及氧化态之间的差异。 最近有人提出在蛋白质的电子传递位点可能存在Fe_4 O_4立方烷。 在这个项目中获得的结果将（1）有助于创建一个光谱？指纹？数据库，用于识别这些图案在自然界中，（2）将用于研究它们的电子状态有关的本地化/离域性质的混合价态，和（3）通过施加外部磁场，将探测在每个氧化态的磁性状态，通过氧化还原修饰的全铁化合物访问。 该项目的智力价值包括对罕见的逐步氧化还原修饰的多铁簇的系统研究。 代表性不足的少数民族学生在本项目期间获得的国际经验和当地无法获得的技术培训构成了本项目的更广泛影响。