High-Nuclearity Metal Carbonyl Clusters

高核羰基金属团簇

• 批准号: 9729555
• 负责人: Lawrence Dahl
• 金额: $ 39万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-04-01 至 2001-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9729555&HistoricalAwards=false
• 关键词: Nuclearity; Metal; Carbonyl; Clusters

Dr. Lawrence F. Dahl of the Department of Chemistry, University of Wisconsin at Madison, is supported by the Inorganic, Bioinorganic, and Organometallic Program of the Chemistry Division to continue his studies on high-nuclearity metal carbonyl clusters. The main thrust of this project is the synthesis, X-ray structural characterization, and structure-bonding analysis of new high-nuclearity (10 or more metal atoms) homo- and hetero-metallic carbonyl clusters. The synthesis of a series of palladium-carbonyl-phosphine clusters will be optimized and extended to include clusters with different phosphine ligands. This series, including a cluster with 59 Pd atoms, will be studied by proton NMR to determine if hydrido-like H atoms are present. New Pd-Ni clusters will be synthesized in sufficient amounts to permit physical/chemical characterization. These clusters will be reacted with phosphine ligands to determine the ligand effect on metal segregation since previous clusters of this type have shown a surprising degree of metal order. A novel carbonyl-phosphine-hydrido cluster with 28 Pd and 12 Pt atoms will be further studied by NMR and hydrogen-deuterium exchange, and synthetically extended by incorporation of additional Pt and Ni atoms. The preparation of a series of Ni-Pd(or Pt)-Rh(or Ir) carbonyl-hydrido clusters with unprecedented metal frameworks will be attempted. The challenging characterization of these unusual clusters will be accomplished by the combination of X-ray crystallography (CCD area detector), electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry, X-ray fluorescence, magnetic susceptibility, and NMR measurements. Theoretical studies on several clusters including a 18-atom Ni-Au cluster will be carried out using density functional methods that include relativistic effects in order to determine the nature of the Ni-Au bonds and to compare the results to those of previous calculations using the Fenske-Hall MO model. Finally, synthetic methods will be improved and optimized to prepare larger amounts of recently discovered 38-metal Au-Pd-Ni and 35-metal Cu-Ni clusters for physical-chemical studies. This project will add fundamental knowledge about bonds between metal atoms, especially ones between different metal types. The large discreet metal clusters also can serve as models for metal particles and surfaces and contribute fundamentally to our understanding of surface science, metal-particle physics, and heterogeneous catalysis. The multi-metal palladium clusters have potential technological importance in the design of new materials with useful catalytic, electronic, magnetic, optical, and hydrogen storage/isotope separation properties. This work also advances state-of-the-art methods of chemical analysis by applying these techniques to extraordinarily demanding problems.

Lawrence F.达勒是哥伦比亚大学化学系的教授， 位于麦迪逊的威斯康星州，由无机，生物无机和 化学系的有机化学课程，以继续他的研究 在高原子核的金属羰基簇上。 这件事的主旨是 项目是合成，X射线结构表征， 新型高成核（10个或更多金属）结构键合分析 原子）同金属和异金属羰基簇。 的合成 一系列钯-羰基-膦簇合物将被优化， 扩展到包括具有不同膦配体的簇。 这 系列，包括一个59个Pd原子的簇，将研究质子 NMR以确定是否存在类似氢原子的H原子。 新的Pd-Ni团簇 将以足够的量合成，以允许物理/化学 特征化 这些簇将与膦配体反应 为了确定配体对金属偏析的影响， 这种类型的簇显示出令人惊讶的金属有序程度。 一 具有28个Pd和12个Pt原子的新型羰基膦-双氢原子簇， 通过NMR和氢-氘交换进一步研究， 通过引入额外的Pt和Ni原子来合成扩展。 一系列Ni-Pd（或Pt）-Rh（或Ir）羰基钯配合物的制备 将尝试具有前所未有的金属框架的簇。 的 对这些不寻常的星团进行具有挑战性的表征将是 通过结合X射线晶体学（CCD区域 傅里叶变换离子回旋加速器 共振质谱，X射线荧光，磁化率， 和NMR测量。 对几种团簇的理论研究， 一个18原子的Ni-Au簇将进行使用密度泛函 方法，包括相对论效应，以确定 性质的Ni-Au键，并比较结果与以前的 使用Fenske-Hall MO模型计算。 最后，合成方法 将得到改进和优化，以准备更多的最近 发现了38个金属Au-Pd-Ni和35个金属Cu-Ni簇合物， 物理化学研究。 这个项目将增加有关金属之间的键的基本知识 原子，特别是不同金属类型之间的原子。 大谨慎 金属团簇也可以作为金属颗粒和表面的模型 并从根本上帮助我们理解表面科学， 金属粒子物理学和多相催化。 多金属 钯簇在设计中具有潜在的技术重要性 新材料的催化，电子，磁性，光学， 和氢存储/同位素分离性能。 这项工作还 通过应用这些先进的化学分析方法， 技术来解决非常苛刻的问题。