Redox-active Metalladiphosphine Ligands for Catalysis

用于催化的氧化还原活性金属二膦配体

• 批准号: 325734342
• 负责人: Professor Dr. Wolfram W. Seidel
• 金额: --
• 依托单位: Metallorganische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/325734342?language=en
• 关键词: Redox; active; Metalladiphosphine; Ligands; Catalysis

The main topic of the research proposal is the development and utilization of redox-active diphosphine ligands based on alkynes, which are substituted by phosphine groups. Alkynes bearing P-atoms in both alpha-positions are excellent bridging ligands. The unsaturated character of the alkyne bridges involves a high electronic cooperativity of the linked metals, which is particularly strong in the side-on carbon phosphine chelate coordination mode. Such cooperativity in dinuclear complexes allows either fast intramolecular electron transfers or even delocalized states over both metals. Accordingly, from an academic prospective the specific electronic structure in those complexes is an intriguing matter of investigation. The systematic development of metalla-acetylenediphosphine ligands and their coordination chemistry is directed to an improvement of catalytic activity of catalytically active P,P-coordinated metals by the electronic coupling of the metals involved. Redox-active phosphines offer the possibility to either switch the donor strength within the catalytic cycle by an intramolecular electron transfer (relay function) or to serve as an electron reservoir for oxidative addition and as a sink for reductive elimination. The latter is particularly interesting for first row transition metals in order to overcome the one-electron redox step limit. In addition, on this basis paramagnetic catalytic systems might become accessible, which are usually diamagnetic in combination with standard phosphines due to their character as strong field ligands. The kind of impact of this virtually distal paramagnetism on the catalytic processes belongs to the central issues of the project. Accordingly, alkyne complexes with terminal phosphine groups are potentially functional ligands; and the use of which in catalysis is generally promising.

本课题的主要课题是开发和利用以膦基取代的炔基氧化还原活性二膦配体。在两个位置都有p原子的炔是很好的桥接配体。炔桥的不饱和特性涉及到连接金属的高电子协同性，特别是在侧对碳膦螯合配位模式下。双核配合物中的这种协同性允许快速的分子内电子转移，甚至允许两种金属的离域状态。因此，从学术的角度来看，这些配合物的特定电子结构是一个有趣的研究问题。金属-乙炔二膦配体及其配位化学的系统发展是为了通过所涉及的金属的电子偶联来提高催化活性P，P配位金属的催化活性。氧化还原活性膦提供了在催化循环中通过分子内电子转移（接力功能）来改变供体强度的可能性，或者作为氧化加成的电子储层和还原消除的电子汇。后者对于第一行过渡金属来说是特别有趣的，以便克服单电子氧化还原步骤限制。此外，在此基础上还可以获得顺磁催化体系，由于其作为强场配体的特性，通常与标准磷化氢结合是抗磁性的。这种几乎远端顺磁性对催化过程的影响属于该项目的中心问题。因此，末端膦基的炔配合物是潜在的功能配体；它在催化中的应用是很有前途的。