Thermal defect engineering of precious group metal–organic frameworks: impact on the catalytic cyclopropanation reaction
Thermal defect engineering of precious group metal–organic frameworks: impact on the catalytic cyclopropanation reaction
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贵族金属有机骨架的热缺陷工程：对催化环丙烷化反应的影响
DOI：
10.1039/d0cy01479f
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发表时间：
2020
影响因子：
5
通讯作者：
R. A. Fischer
中科院分区：
文献类型：
--
作者：
W. R. Heinz;R. Junk;I. Aguirrezabal-Telleria;B. Bueken;H. Bunzen;T. Gölz;M. Cokoja;D. De Vos;R. A. Fischer
本文报道了基于贵金属（PGM）的类似物（RhII，II, RuII，II, RuII, RuII，III）的缺陷工程，并利用苯乙烯与重氮乙酸乙酯（EDA）的环丙化反应作为分析探针，研究了复杂金属-有机框架（MOF）结构。我们通过活性、产物分布和立体选择性表征了扩展框架内的活性位点。阐明了金属的作用、氧化态和开放金属位的可用性。通过17个样品，包括参考Cu-HKUST-1，金属纳米颗粒和现有文献，提出了在自支撑多孔和晶体框架内桨轮配合物可调性的结论。特别是，额外的轴向配体（OAc−/Cl−）在混合价RuII，III节点上的电荷补偿似乎是催化过程中副产物形成的原因。热缺陷工程允许控制和优先去除这些轴向配体，同时降低平均金属氧化态。这增加了开放金属位（OMS）的数量和催化活性，并提高了对环丙烷的化学选择性。对形成反式环丙烷的偏爱是归因于桨轮部分的空间拥挤。随着改良桨轮节点的PGM-HKUST-1类似物缺陷的增加，这种非对构选择性逐渐减弱。
We report on the engineering of defects in precious group metal (PGM)-based HKUST-1 (Hong Kong University of Science and Technology) analogues (RhII,II, RuII,II, RuII,III) and the ramification on the catalytic activity by using the cyclopropanation of styrene with ethyl diazoacetate (EDA) as an analytical probe to investigate complex metal–organic framework (MOF) structures. We have characterized the active sites within the extended frameworks by their activity, product distribution and stereoselectivity. The role of the metal, its oxidation state and the availability of open metal sites is elucidated. With a set of 17 samples including reference to Cu-HKUST-1, metal nanoparticles and existing literature, conclusions on the tuneability of paddlewheel complexes within self-supported porous and crystalline frameworks are presented. In particular, additional axial ligands (OAc−/Cl−) accounting for charge compensation at the mixed-valent RuII,III nodes seem responsible for side-product formation during catalysis. Thermal defect-engineering allows for controlled and preferential removal of those axial ligands accompanied by reduction of the average metal oxidation state. This enhances the number of open metal sites (OMS) and the catalytic activity as well as improving the chemoselectivity towards cyclopropanes. The preference towards formation of trans-cyclopropane is assigned to the steric crowding of the paddlewheel moiety. This diastereoselectivity gradually diminishes with rising defectiveness of the PGM-HKUST-1 analogues featuring modified paddlewheel nodes.
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影响因子：
19
作者：
Jin‐Liang Zhuang;D. Ceglarek;S. Pethuraj;A. Terfort
通讯作者：
Jin‐Liang Zhuang;D. Ceglarek;S. Pethuraj;A. Terfort
通过固态核磁共振技术揭示多相二钠催化剂的结构反应关系
影响因子：
3.7
作者：
P. Braga-Groszewicz;Q. Wen;A.S. Lilly Thankamony;B.Zhang;U. Kunz;G. Sauer;T. Gutmann;G. Buntkowsky
通讯作者：
G. Buntkowsky
二铑(II)配体对金属卡宾反应活性和选择性的影响
DOI：
10.1002/chin.200230284
发表时间：
2002
期刊：
ChemInform
影响因子：
--
作者：
M. Doyle;T. Ren
通讯作者：
T. Ren
影响因子：
15
作者：
DOYLE, MP;WESTRUM, LJ;PEARSON, MM
通讯作者：
PEARSON, MM
通过催化剂工程从烯烃环丙烷化到烯烃复分解：烯烃复分解在精细有机合成和高分子化学中的最新应用
DOI：
--
发表时间：
1998
期刊：
影响因子：
--
作者：
A. Noels;A. Demonceau
通讯作者：
A. Demonceau