Iron hexamesityl-5,15-diazaporphyrin: synthesis, structure and catalytic use for direct oxidation of sp3 C–H bonds

Dalton Transactions ◽

10.1039/d1dt00893e ◽

2021 ◽

Author(s):

Tsubasa Nishimura ◽

Takahiro Sakurai ◽

Hiroshi Shinokubo ◽

Yoshihiro Miyake

Keyword(s):

Catalytic Oxidation ◽

High Performance ◽

Catalyst Deactivation ◽

Direct Oxidation

Iron hexamesityl-5,15-diazaporphyrin was successfully synthesized. Its use for catalytic oxidation of cyclooctane showed high performance with a total TON up to 731. The introduction of bulky mesityl groups prevented the catalyst deactivation via formation of a μ-oxo dimer.

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High-performance (La,Sr)(Cr,Mn)O3/(Gd,Ce)O2−δ composite anode for direct oxidation of methane

Journal of Power Sources ◽

10.1016/j.jpowsour.2006.11.075 ◽

2007 ◽

Vol 165 (1) ◽

pp. 34-40 ◽

Cited By ~ 38

Author(s):

X.J. Chen ◽

Q.L. Liu ◽

K.A. Khor ◽

S.H. Chan

Keyword(s):

High Performance ◽

Composite Anode ◽

Direct Oxidation ◽

Oxidation Of Methane

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Mechanism of selective benzene hydroxylation catalyzed by iron-containing zeolites

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1813849115 ◽

2018 ◽

Vol 115 (48) ◽

pp. 12124-12129 ◽

Cited By ~ 3

Author(s):

Benjamin E. R. Snyder ◽

Max L. Bols ◽

Hannah M. Rhoda ◽

Pieter Vanelderen ◽

Lars H. Böttger ◽

...

Keyword(s):

High Activity ◽

Active Site ◽

Active Sites ◽

High Performance ◽

Density Functional ◽

Catalyst Deactivation ◽

Density Functional Theory Calculations ◽

Oxidation Catalysis ◽

Spectroscopic Techniques ◽

Benzene Hydroxylation

A direct, catalytic conversion of benzene to phenol would have wide-reaching economic impacts. Fe zeolites exhibit a remarkable combination of high activity and selectivity in this conversion, leading to their past implementation at the pilot plant level. There were, however, issues related to catalyst deactivation for this process. Mechanistic insight could resolve these issues, and also provide a blueprint for achieving high performance in selective oxidation catalysis. Recently, we demonstrated that the active site of selective hydrocarbon oxidation in Fe zeolites, named α-O, is an unusually reactive Fe(IV)=O species. Here, we apply advanced spectroscopic techniques to determine that the reaction of this Fe(IV)=O intermediate with benzene in fact regenerates the reduced Fe(II) active site, enabling catalytic turnover. At the same time, a small fraction of Fe(III)-phenolate poisoned active sites form, defining a mechanism for catalyst deactivation. Density-functional theory calculations provide further insight into the experimentally defined mechanism. The extreme reactivity of α-O significantly tunes down (eliminates) the rate-limiting barrier for aromatic hydroxylation, leading to a diffusion-limited reaction coordinate. This favors hydroxylation of the rapidly diffusing benzene substrate over the slowly diffusing (but more reactive) oxygenated product, thereby enhancing selectivity. This defines a mechanism to simultaneously attain high activity (conversion) and selectivity, enabling the efficient oxidative upgrading of inert hydrocarbon substrates.

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Catalytic oxidation of ascorbic acid via copper–polypyridyl complex immobilized on glass

RSC Advances ◽

10.1039/c4ra00817k ◽

2014 ◽

Vol 4 (44) ◽

pp. 23168-23176 ◽

Cited By ~ 16

Author(s):

Vikram Singh ◽

Prakash Chandra Mondal ◽

Megha Chhatwal ◽

Yekkoni Lakshmanan Jeyachandran ◽

Michael Zharnikov

Keyword(s):

Ascorbic Acid ◽

Catalytic Oxidation ◽

High Performance ◽

Polypyridyl Complexes ◽

Polypyridyl Complex ◽

Redox Active ◽

Glass Support

A monolayer of redox-active copper–polypyridyl complexes on glass support was utilized for catalytic oxidation of ascorbic acid showing high performance.

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