Otte Kaitlyn S, Niklas Julie E, Studvick Chad M, Montgomery Charlotte L, Bredar Alexandria R C, Popov Ivan A, La Pierre Henry S
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States.
Department of Chemistry, University of Akron, Akron, Ohio 44325-3601, United States.
J Am Chem Soc. 2024 Aug 7;146(31):21859-21867. doi: 10.1021/jacs.4c06319. Epub 2024 Jul 25.
The synthesis and solution and solid-state characterization of [Pu(NPC)], , (NPC = [NPBu(pyrr)]; Bu = C(CH); pyrr = pyrrolidinyl) and [Pu(NPC)][K(2.2.2.-cryptand)], , is described. Cyclic voltammetry studies of reveal a quasi-reversible Pu couple, an irreversible Pu couple, and a third couple evincing a rapid proton-coupled electron transfer (PCET) reaction occurring after the electrochemical formation of Pu. The chemical identity of the product of the PCET reaction was confirmed by independent chemical synthesis to be [Pu(NPC)(HNPC)][B(ArF)], , (B(ArF) = tetrakis(2,3,4,5,6-pentafluourophenyl)borate) via two mechanistically distinct transformations of : protonation and oxidation. The kinetics and thermodynamics of this PCET reaction are determined via electrochemical analysis, simulation, and density functional theory. The computational studies demonstrate a direct correlation between the changing nature of 5 and 6 orbital participation in metal-ligand bonding and the electron density on the N atom with the thermodynamics of the PCET reaction from Np to Pu, and an indirect correlation with the roughly 5-orders of magnitude faster Pu PCET compared to Np for the An species.
描述了[Pu(NPC)]（NPC = [NPBu(pyrr)]；Bu = C(CH)；pyrr = 吡咯烷基）和[Pu(NPC)][K(2.2.2.-穴醚)]的合成、溶液和固态表征。对 的循环伏安法研究揭示了一个准可逆的Pu电对、一个不可逆的Pu电对以及第三个电对，该电对表明在电化学形成Pu后发生了快速的质子耦合电子转移（PCET）反应。通过独立化学合成证实PCET反应产物的化学身份为[Pu(NPC)(HNPC)][B(ArF)]（B(ArF) = 四(2,3,4,5,6 - 五氟苯基)硼酸酯），这是通过 的两种机制不同的转化实现的：质子化和氧化。通过电化学分析、模拟和密度泛函理论确定了该PCET反应的动力学和热力学。计算研究表明，5和6轨道参与金属 - 配体键合的性质变化与N原子上的电子密度之间存在直接关联，这与从Np到Pu的PCET反应的热力学相关，并且与An物种中Pu的PCET比Np快约5个数量级存在间接关联。
