Copper ion is a versatile and ubiquitous facilitator of redox chemical and biochemical processes. These include the binding of molecular oxygen to copper(I) complexes where it undergoes stepwise reduction-protonation. A detailed understanding of thermodynamic relationships between such reduced/protonated states is key to elucidate the fundamentals of the chemical/biochemical processes involved. The dicopper(I) complex [Cu^I₂(BPMPO^–)]¹⁺ {BPMPOH = 2,6-bis{[(bis(2-pyridylmethyl)amino]methyl}-4-methylphenol)} undergoes cryogenic dioxygen addition; further manipulations in 2-methyltetrahydrofuran generate dicopper(II) peroxo [Cu^II₂(BPMPO^–)(O₂^2–)]¹⁺, hydroperoxo [Cu^II₂(BPMPO^–)(⁻OOH)]²⁺, and superoxo [Cu^II₂(BPMPO^–)(O₂^•–)]²⁺ species, characterized by UV–vis, resonance Raman and electron paramagnetic resonance (EPR) spectroscopies, and cold spray ionization mass spectrometry. An unexpected EPR spectrum for [Cu^II₂(BPMPO^–)(O₂^•–)]²⁺ is explained by the analysis of its exchange-coupled three-spin frustrated system and DFT calculations. A redox equilibrium, [Cu^II₂(BPMPO^–)(O₂^2–)]¹⁺ ⇄ [Cu^II₂(BPMPO^–)(O₂^•–)]²⁺, is established utilizing Me₈Fc⁺/Cr(η⁶-C₆H₆)₂, allowing for [Cu^II₂(BPMPO^–)(O₂^•–)]²⁺/[Cu^II₂(BPMPO^–)(O₂^2–)]¹⁺ reduction potential calculation, E°′ = −0.44 ± 0.01 V vs Fc^+/0, also confirmed by cryoelectrochemical measurements (E°′ = −0.40 ± 0.01 V). 2,6-Lutidinium triflate addition to [Cu^II₂(BPMPO^–)(O₂^2–)]¹⁺ produces [Cu^II₂(BPMPO^–)(⁻OOH)]²⁺; using a phosphazene base, an acid–base equilibrium was achieved, pK_a = 22.3 ± 0.7 for [Cu^II₂(BPMPO^–)(⁻OOH)]²⁺. The BDFE_OO–H = 80.3 ± 1.2 kcal/mol, as calculated for [Cu^II₂(BPMPO^–)(⁻OOH)]²⁺; this is further substantiated by H atom abstraction from O–H substrates by [Cu^II₂(BPMPO^–)(O₂^•–)]²⁺ forming [Cu^II₂(BPMPO^–)(⁻OOH)]²⁺. In comparison to known analogues, the thermodynamic and spectroscopic properties of [Cu^II₂(BPMPO^–)] O₂-derived adducts can be accounted for based on chelate ring size variations built into the BPMPO^– framework and the resulting enhanced Cu^II-ion Lewis acidity.

中文翻译：

---

双核铜双氧衍生的（氢）过氧和超氧物种内的配位变化；对热力学和电子性能的影响

铜离子是氧化还原化学和生化过程的多功能且普遍存在的促进剂。这些包括分子氧与铜（I）配合物的结合，并在其中经历逐步还原-质子化。详细了解此类还原/质子化状态之间的热力学关系是阐明所涉及的化学/生化过程的基本原理的关键。二铜(I)络合物[Cu ^I ₂ (BPMPO ^– )] ¹⁺ {BPMPOH = 2,6-bis{[(双(2-吡啶基甲基)氨基]甲基}-4-甲基苯酚)}进行低温双氧加成；在2-甲基四氢呋喃中进一步操作生成二铜(II)过氧[Cu ^II ₂ (BPMPO ^– )(O ₂ ^2– )] ¹⁺、氢过氧[Cu ^II ₂ (BPMPO ^– )( ⁻ OOH)] ²⁺和超氧[ Cu ^II ₂ (BPMPO ^– )(O ₂ ^•– )] ²⁺物质，通过紫外可见光谱、共振拉曼光谱和电子顺磁共振 (EPR) 光谱以及冷喷雾电离质谱进行表征。 [Cu ^II ₂ (BPMPO ^– )(O ₂ ^•– )] ²⁺的意外 EPR 谱通过对其交换耦合三自旋受抑系统和 DFT 计算的分析进行了解释。利用 Me ₈ Fc ⁺ /Cr(建立氧化还原平衡 [Cu ^II ₂ (BPMPO ^– )(O ₂ ^2– )] ¹⁺ ⇄ [Cu ^II ₂ (BPMPO ^– )(O ₂ ^•– )] ²⁺ η ⁶ -C ₆ H ₆ ) ₂，可进行 [Cu ^II ₂ (BPMPO ^– )(O ₂ ^•– )] ²⁺ /[Cu ^II ₂ (BPMPO ^– )(O ₂ ^2– )] ¹⁺还原电位计算，E °′ = -0.44 ± 0.01 V vs Fc ^+/0，也通过低温电化学测量证实（E °′ = -0.40 ± 0.01 V）。 2,6-三氟甲磺酸镨与 [Cu ^II ₂ (BPMPO ^– )(O ₂ ^2– )] ¹⁺加成生成 [Cu ^II ₂ (BPMPO ^– )(^- OOH)] ²⁺ ;使用磷腈碱，实现酸碱平衡， [Cu ^II ₂ (BPMPO ^– )( ⁻ OOH)] ^2+的_p Ka = 22.3 ± 0.7 。 BDFE _OO–H = 80.3 ± 1.2 kcal/mol，根据 [Cu ^II ₂ (BPMPO ^– )( ⁻ OOH)] ²⁺计算；通过 [Cu ^II ₂ (BPMPO ^– )(O ₂ ^•– )] ²⁺从 O–H 底物中提取 H 原子形成 [Cu ^II ₂ (BPMPO ^– )( ⁻ OOH)] ²⁺进一步证实了这一点。与已知的类似物相比，[Cu ^II ₂ (BPMPO ^– )] O ₂衍生加合物的热力学和光谱性质可以根据 BPMPO ^–骨架中内置的螯合环尺寸变化以及由此产生的增强的 Cu ^{II -}离子来解释路易斯酸度。