ELECTRONIC AND GEOMETRIC ORIGINS OF THE NON-INNOCENT NATURE OF LIGANDS

配体非无辜性质的电子和几何起源

• 批准号: 8362180
• 负责人: Robert Karoly Szilagyi
• 金额: $ 0.14万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8362180
• 关键词: Behavior; Binding Sites; Catalysis; Chemicals; Data; Electronics; Funding; Grant; Guidelines; Investigation; Ions; Ligands; Measurement; Metals; Molecular; Mono-S; National Center for Research Resources; Nature; Nitrogen; Organometallic Chemistry; Oxidation-Reduction; Oxygen; Phosphorus; Principal Investigator; Radiation; Research; Research Infrastructure; Resources; Series; Source; Sulfur; Support System; System; Transition Elements; Translating; United States National Institutes of Health; absorption; base; cost; scaffold; structural biology

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We propose multi-edge x-ray absorption studies to dissect the fundamental molecular details of the non-innocent behavior of ligands in coordination compounds. The non-innocent nature of ligands is best characterized macroscopically by ligand-based reactivity, where the central metal becomes a spectator and most often a steric scaffold rather than a reactive site. Microscopically this translates into valence orbitals that are rich in ligand contribution (i.e. large ligand covalency). We have already collected preliminary data for formally Ni(II)/Ni(III) redox couple system supported with a pincer-type ligand denoted PNP (PNP = N[2-P(CHMe2)2-4-methylphenyl]2) at the Ni L-, Cl and P K-edges that clearly demonstrate the feasibility of our measurements. Our data unexpectedly show the non-innocent behavior of the pincer-type ligand PNP originally thought to be innocent ancillary in the context of organometallic chemistry and catalysis. Previously this behavior was mainly observed for sulfur and oxygen containing ligands, such as dithiolenes and catecholes. We first plan to study two pincer-type ligands with PCP and PNP compositions that are coordinated to a series of first row transition metals as central metals in their formally mono-, di-, and trivalent forms. Given the reducing ability of phosphorus, we will also investigate pincer ligands having only nitrogen donors, specifically the monoanionic NCN system C6H3[1,3-CH2NiPr2]2. These proposed investigations are part of a larger project aiming to understand the physical-chemical factors that can contribute to non-innocent behavior as a function of the 3d transition metal ion (when shifting from late to mid) and the nature of the heteroatom in the ligand. We wish to set up guidelines for synthetic chemists to be able a priori predict non-innocent behavior.

该副本是利用资源的众多研究子项目之一 由NIH/NCRR资助的中心赠款提供。对该子弹的主要支持 而且，副投影的主要研究员可能是其他来源提供的 包括其他NIH来源。 列出的总费用可能 代表subproject使用的中心基础架构的估计量， NCRR赠款不直接向子弹或副本人员提供的直接资金。 我们提出了多边X射线吸收研究，以剖析配位化合物中配体非一种中性行为的基本分子细节。配体的非纯性质是通过基于配体的反应性宏观表征的，其中中央金属成为观众，通常是空间支架而不是反应性位点。从显微镜上看，这转化为富含配体贡献（即大配体共价）的价轨道。我们已经收集了以钳子型配体为pNP（pNP = n [2-p（chme2）2-4-甲基苯基] 2）支撑的正式Ni（ii）/Ni（ii）/Ni（ii）/Ni（ii）/Ni（iii）（III）氧化还原夫妇系统2）在Ni L-，Cl和P K-Edges上表现出了清晰的效率。我们的数据出乎意料地表明，在有机金属化学和催化的背景下，钳子型配体PNP最初被认为是无辜的辅助行为。以前，对于含有二硫代烯和catecholes等配体的硫和氧气的主要观察到了这种行为。我们首先计划使用PCP和PNP组合物研究两种钳子型配体，这些配体与一系列第一排过渡金属协调为中央金属，它们是其正式单，二，三价形式的中央金属。鉴于磷的降低能力，我们还将研究只有氮供体的钳子配体，特别是单氨基NCN系统C6H3 [1,3-CH2NIPR2] 2。这些提出的研究是一个较大项目的一部分，旨在了解可以导致非自然行为作为3D过渡金属离子的函数（从后期到中期转移到中间）以及配体中杂原子的性质的函数的物理化学因素。我们希望为合成化学家制定准则，以便先验预测非一家人的行为。