Coordination-Induced Bond Weakening and Electrocatalytic Proton-Coupled Electron Transfer of a Ruthenium Verdazyl Complex
作者:Conor M. Galvin、Daniel P. Marron、Julia M. Dressel、Robert M. Waymouth
DOI:10.1021/acs.inorgchem.3c02775
日期:2024.1.15
increased acidity is in part attributable to stabilization of the conjugate base Vd–. When free, Vd– distorts to avoid an 8πe– antiaromatic state, but it remains planar when bound to Ru. Proton-coupled electron transfer (PCET) behavior is observed for both the free and metalated leucoverdazyls. PCET equilibrium between the Vd radical and TEMPOH affords a VdH BDFE that is in good agreement with that obtained
leucoverdazyl配体2,4-二异丙基-6-(吡啶-2-基)-1,4-二氢-1,2,4,5-四嗪-3(2 H )-one VdH与Ru的配位显着削弱了配体的 N-H 键。电化学测量表明,金属化的 leucoverdazyl Ru( VdH )(乙酰丙酮) 2 RuVdH比游离配体具有更低的 p Ka (−5 单位)、BDFE (−7 kcal/mol) 和水度 (−22 kcal/mol) 。 DFT 计算表明,酸度的增加部分归因于共轭碱Vd –的稳定。当自由时, Vd –扭曲以避免 8πe –反芳香族状态,但当与 Ru 结合时它保持平面。对于游离的和金属化的亮盖达唑都观察到质子耦合电子转移(PCET)行为。 Vd自由基和 TEMPOH 之间的 PCET 平衡提供了VdH BDFE,与电化学方法获得的结果非常一致。 RuVd表现出电催化 PCET 供体行为。在酸性条件下,它通过RuVdH的净1e