Effects of Charged Ligand Substituents on the Properties of the Formally Copper(III)-Hydroxide ([CuOH](2+)) Unit.
Effects of Charged Ligand Substituents on the Properties of the Formally Copper(III)-Hydroxide ([CuOH](2+)) Unit.
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DOI：
10.1021/acs.inorgchem.8b01529
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发表时间：
2018-08-20
影响因子：
4.6
通讯作者：
Tolman WB
中科院分区：
文献类型：
--
作者：
Dhar D;Yee GM;Tolman WB
为了了解远端电荷如何影响[CuOH]2+核心的性质和氢原子转移（HAT）反应性，提出了在氧化催化中重要的目标，（M = [K（18-冠-6）]+或[K（crypt-222）]+）和[NMe 3LCuOH]X（X = BArF 4 −或ClO 4 −），其中SO 3 −或NMe 3+取代基占据支持性双（羧酰胺）吡啶配体的侧翼芳环的帕拉。结构和光谱表征表明，相应配合物中的[CuOH]+核心是相似的，但循环伏安法显示[CuOH]2+/[CuOH]+电对的E1/2值对[NMe 3LCuOH]2+比[SO 3LCuOH]−物种的氧化性高出近0.3 V，后者受到远端− SO 3 −取代基与K+或Na+反离子之间的相互作用的影响。配合物的化学氧化产生相应的[CuOH]2+物种，如紫外维斯光谱所示。测量了这些物种与9，10-二氢蒽的HAT反应生成相应的[Cu（OH 2）]2+络合物和蒽的速率，并通过测定产物O-H键的键解离常数（BDEs）来评估该过程的热力学。[SO 3LCuOH]−的HAT速率比[NMe 3LCuOH]2+快150倍，尽管发现产物O−H键的BDE大致相同。这些意见和新的见解的支持配体属性的[CuOH]2+单元的属性的作用的materales。
With the goal of understanding how distal charge influences the properties and hydrogen atom transfer (HAT) reactivity of the [CuOH]2+ core proposed to be important in oxidation catalysis, the complexes [M]3[SO3LCuOH] (M = [K(18-crown-6)]+ or [K(crypt-222)]+) and [NMe3LCuOH]X (X = BArF4− or ClO4−) were prepared, in which SO3− or NMe3+ substituents occupy the para positions of the flanking aryl rings of the supporting bis(carboxamide)pyridine ligands. Structural and spectroscopic characterization showed that the [CuOH]+ cores in the corresponding complexes were similar, but cyclic voltammetry revealed the E1/2 value for the [CuOH]2+/[CuOH]+ couple to be nearly 0.3 V more oxidizing for the [NMe3LCuOH]2+ than the [SO3LCuOH]− species, with the latter influenced by interactions between the distal −SO3− substituents and K+ or Na+ counterions. Chemical oxidations of the complexes generated the corresponding [CuOH]2+ species as evinced by UV−vis spectroscopy. The rates of HAT reactions of these species with 9,10-dihydroanthracene to yield the corresponding [Cu(OH2)]2+ complexes and anthracene were measured, and the thermodynamics of the processes were evaluated via determination of the bond dissociation enthalpies (BDEs) of the product O−H bonds. The HAT rate for [SO3LCuOH]− was found to be ∼150 times faster than that for [NMe3LCuOH]2+, despite finding approximately the same BDEs for the product O−H bonds. Rationales for these observations and new insights into the roles of supporting ligand attributes on the properties of the [CuOH]2+ unit are presented.
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DOI：
10.1021/jp8093947
发表时间：
2009-04-30
期刊：
The journal of physical chemistry. A
影响因子：
--
作者：
Bales BL;Meyer M;Smith S;Peric M
通讯作者：
Peric M
影响因子：
62.1
作者：
Elwell CE;Gagnon NL;Neisen BD;Dhar D;Spaeth AD;Yee GM;Tolman WB
通讯作者：
Tolman WB
影响因子：
3.3
作者：
Bales, BL;Peric, M
通讯作者：
Peric, M
高反应性P450模型化合物I。
影响因子：
15
作者：
Bell, Seth R.;Groves, John T.
通讯作者：
Groves, John T.
通过铜（III） - 羟基复合物从碳氢化合物中抽象氢原子。
影响因子：
15
作者：
Dhar, Debanjan;Tolman, William B.
通讯作者：
Tolman, William B.