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一个单核Mn^III-氧复合物的反应场景与过氧化

Elizabeth N Grotemeyer¹, Joshua D Parham¹, Timothy A Jackson¹

¹The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, KS 66045, USA. taj@ku.edu.

Dalton transactions (Cambridge, England : 2003)

|September 28, 2023

概括

研究人员观察到难以捉摸的过氧中间体,这是催化过程的关键. 他们在不同的条件下控制了bis-μ-oxo-dimanganese,Mn-III-hydroperoxo和Mn-III-peroxo复合物的形成.

科学领域:

无机化学无机化学无机化学
生物有机化学生物有机化学
催化剂是一种催化剂.

背景情况:

过氧的物种被提议在酶和合成催化剂循环中作为关键中间体.
对这些中间体的直接观察是有限的,阻碍了机理学理解.

研究的目的:

为了合成和表征难以捉摸的过氧中间体.
为了研究单核Mn^III-hydroxo复合物与过氧化的反应.
阐明控制不同中间体形成的因素.

主要方法:

在各种条件下[Mn^III(OH) ((dpaq^2Me) ]⁺与过氧化的反应.
光谱技术:电子吸收,H NMR,EPR,X射线吸收等.
计算方法:密度函数理论 (DFT) 和完全活动空间自相一致场 (CASSCF) 计算.

主要成果:

控制的三种不同的过氧中间体的形成:bis(μ-oxo) dimanganese(III,IV) 复合物[Mn^IIIMn^IV(μ-O) ₂(dpaq^2Me) ₂]⁺,Mn^III-hydroperoxo复合物[Mn^III(OOH) dpaq^2Me) ]⁺,以及Mn^III-peroxo复合物[Mn^III^{O²) ].}
MnIII-hydroperoxo形成模仿了合成催化剂激活过氧化的拟议初级步骤.

结论:

成功观察和表征了关键的过氧中介物.
通过调整反应条件 (酸度,H2度) 来证明对中间体形成的控制.
提供了对基于的过氧化激活机制的见解,这与生物和合成系统相关.

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