Department of Chemistry, Center for Metals in Biocatalysis, and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States.
J Am Chem Soc. 2011 Nov 9;133(44):17602-5. doi: 10.1021/ja207882h. Epub 2011 Oct 17.
One-electron oxidation of the tetragonal Cu(II) complex [Bu(4)N][LCuOH] at -80 °C generated the reactive intermediate LCuOH, which was shown to be a Cu(III) complex on the basis of spectroscopy and theory (L = N,N'-bis(2,6-diisopropylphenyl)-2,6-pyridinedicarboxamide). The complex LCuOH reacts with dihydroanthracene to yield anthracene and the Cu(II) complex LCu(OH(2)). Kinetic studies showed that the reaction occurs via H-atom abstraction via a second-order rate law at high rates (cf. k = 1.1(1) M(-1) s(-1) at -80 °C, ΔH(‡) = 5.4(2) kcal mol(-1), ΔS(‡) = -30(2) eu) and with very large kinetic isotope effects (cf. k(H)/k(D) = 44 at -70 °C). The findings suggest that a Cu(III)-OH moiety is a viable reactant in oxidation catalysis.
在-80°C 下，四方形 Cu(II) 配合物 [Bu(4)N][LCuOH] 的单电子氧化生成了反应性中间体 LCuOH，基于光谱和理论（L = N，N'-双（2,6-二异丙基苯基）-2,6-吡啶二羧酸酰胺）表明其为 Cu(III) 配合物。该配合物 LCuOH 与二氢蒽反应生成蒽和 Cu(II) 配合物 LCu(OH(2))。动力学研究表明，该反应通过 H 原子的攫取以二级速率定律在高反应速率下发生（在-80°C 下，k = 1.1(1) M(-1) s(-1)，ΔH(‡) = 5.4(2) kcal mol(-1)，ΔS(‡) = -30(2) eu），并且具有非常大的动力学同位素效应（在-70°C 下，k(H)/k(D) = 44）。这些发现表明 Cu(III)-OH 部分是氧化催化中的一种可行反应物。
