Synthetic Manipulation of Main Group Elements with Transition Metal Isocyanides

过渡金属异氰化物对主族元素的合成操作

• 批准号: 2247629
• 负责人: Joshua Figueroa
• 金额: $ 57.5万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2247629&HistoricalAwards=false
• 关键词: Synthetic; Manipulation; Main; Group; Elements

With the support of the Chemical Synthesis program in the Division of Chemistry, Professor Joshua S. Figueroa of the University of California, San Diego will study how the chemistry and behavior of main-group elements can be controlled and modulated by transition metal compounds featuring isocyanide supporting groups. The isocyanide supporting groups used in the context of this project provide a protective shield for the chemical interactions between the transition metal and main-group elements. This shield, in turn, allows for the preparation and isolation of molecules that are usually unstable and difficult to obtain. A specific focus of this award is to use iron isocyanide compounds to study and understand the fundamental properties and chemical reactivity of the diatomic molecules boron monofluoride (BF) and diphosphorus. Boron monofluoride, as a free molecule, is not stable under ambient conditions on account of the extreme bonding polarization. Similarly, diphosphorus, unlike its lighter analogue dinitrogen, is also not a stable molecule under normal conditions, preferring instead to condense into polyphosphorus solid materials. With the advent of the m-terphenyl isocyanide supporting groups, stable molecules containing both BF and diphosphorus have been prepared. In the course of this award, detailed investigations into the fundamental nature of BF and diphosphorus will be conducted. These investigations seek to provide answers to basic questions, including 1) how do metal-bound BF and diphosphorus react with other molecules, 2) how do BF and diphosphorus influence the chemical behavior on the metals to which they are bound and, 3) how does the reactivity of metal-bound BF and diphosphorus compare to that of the free, yet unstable, molecules? This project will also focus on the preparation and characterization of other transition-metal-supported main-group element species, with a specific emphasis on generating other unusual or unknown diatomic molecules. The broader impacts activities will include student research training and mentoring, the development of a hands-on laboratory safety course for incoming graduate students, and mentorship of transfer students.This project will specifically focus on the synthesis and reactivity of unusual main-group fragments stabilized by transition-metal m-terphenyl isocyanide complexes. Building on recent reports disclosing the synthesis of an iron terminal boron monofluoride (BF) complex, and a mononuclear diphosphorus complex of iron, detailed investigations will be conducted that aim to elucidate the reactivity of these unusual diatomic ligands with exogenous substrates as well as their specific influence on the transition metal centers to which they are bound. For the terminal BF complex specifically, synthetic studies will be conducted that aim to expand on the pronounced electrophilicity of the boron center, while at the same time detailing reaction profiles that result in the cleavage of the BF unit en route to other metal-boron complexes. In the case of the mononuclear diphosphorus iron complex, its side-on binding mode presents the opportunity to expound upon the fundamental periodic diagonal relationship between phosphorus and carbon. Accordingly, reactivity studies will be conducted that aim to compare and contrast the reactivity of metal-stabilized diphosphorus with that of acetylene and other substituted alkynes. Specific to these efforts will be an assessment of the scope of Diels-Alder-type reactivity between side-on coordinated diphosphorus and organic dienes. In addition, based on preliminary evidence, the electrophilic character of the side-on coordinated diphosphorus with a range of nucleophilic substrates will be evaluated. In parallel to investigations into the nature of BF and diphosphorus coordinated to iron, other low-valent transition metal m-terphenyl isocyanide complexes will be prepared and/or studied with respect to their ability to stabilize unusual main-group fragments, with a focus on the preparation of other unstable or unknown diatomic molecules, especially of the heavier p-block elements. An additional emphasis will be placed on the synthesis of BF complexes of other transition metals in an effort to test electronic structure hypotheses on the factors, electronic environment(s) and conditions that are required to stabilize this reactive diatomic molecule.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.

在化学合成计划的支持下，加利福尼亚大学的Joshua S. Figueroa教授将研究如何通过具有异氰酸酯支持组的过渡金属化合物来控制和调节主元素的化学和行为。该项目背景下使用的异氰化物支撑组为过渡金属和主组元件之间的化学相互作用提供了保护屏蔽。反过来，这种盾牌允许制备和隔离通常不稳定且难以获得的分子。该奖项的一个特定重点是使用异氰化铁化合物研究和了解双原子分子硼氟烷（BF）和双磷的基本特性和化学反应性。由于极端粘结极化，在环境条件下，单氟硼醇作为游离分子不稳定。同样，与较轻的类似物的二氮不同，双磷在正常条件下也不是稳定的分子，而是宁愿将其凝结成多磷固体材料中。随着M-甲苯基异氰化物支撑组的出现，已经制备了包含BF和双磷的稳定分子。在该奖项的过程中，将对BF和Diphosphorus的基本性质进行详细的研究。这些调查旨在为基本问题提供答案，包括1）金属结合的BF和双磷与其他分子反应，2）BF和Diphosphorus如何影响其绑定金属上的化学行为，以及，3）3）金属结合的BF和Diphosphorus的反应性如何与自由的自由相结合，但分子，分子，分子，分子分子？该项目还将集中于其他过渡金属支撑的主要元素物种的制备和表征，并特别强调产生其他不寻常或未知的双原子分子。更广泛的影响活动将包括学生研究培训和指导，为入学生的动手实验室安全课程的开发以及转学学生的指导。该项目将特别关注通过过渡金属M- Terphenylysocyanynide Complextes稳定的异常主体片段的综合和反应性。基于最近的报道，揭示了铁末端单氟化铁（BF）复合物的合成以及铁的单核双磷酶复合物的详细研究，旨在阐明这些异常的硅藻配体的反应性，这些配体具有外源底物以及它们对过渡金属的特定影响，它们是限制金属的特定影响。对于末端BF复合物，将进行合成研究，旨在扩展硼中心的明显亲电性，同时详细介绍导致BF单位在其他金属硼配合物中裂解的反应曲线。在单核双磷铁络合物的情况下，其侧面结合模式为阐述了磷和碳之间基本周期性对角线关系的机会。因此，将进行反应性研究，旨在比较和对比金属稳定的双磷与乙炔和其他取代炔的反应性。这些努力的特异性将评估侧面协调的双磷和有机二烯之间的Diels-Alder-Alder-Alder型反应性范围。此外，基于初步证据，将评估侧面协调的双磷与一系列亲核底物的亲电性。 In parallel to investigations into the nature of BF and diphosphorus coordinated to iron, other low-valent transition metal m-terphenyl isocyanide complexes will be prepared and/or studied with respect to their ability to stabilize unusual main-group fragments, with a focus on the preparation of other unstable or unknown diatomic molecules, especially of the heavier p-block elements. An additional emphasis will be placed on the synthesis of BF complexes of other transition metals in an effort to test electronic structure hypotheses on the factors, electronic environment(s) and conditions that are required to stabilize this reactive diatomic molecule.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.