scholarly journals Statistical analysis of C–H activation by oxo complexes supports diverse thermodynamic control over reactivity

2021 ◽  
Author(s):  
Joseph E. Schneider ◽  
McKenna K. Goetz ◽  
John S. Anderson
Keyword(s):  
Electron Transfer ◽  
Free Energy ◽  
Statistical Analysis ◽  
Transition Metal ◽  
Thermodynamic Control ◽  
Oxo Complexes ◽  
Thermodynamic Factors

Statistical analysis of transition metal oxo mediated C–H activation indicates that thermodynamic factors dictate reactivity and that the energetics of proton and electron transfer have effects independent of the free energy of the reaction.

Photooxidation of Cyclohexane with Dioxygen in Acetonitrile in the Presence of Transition Metal Chlorides

1992 ◽  
Vol 57 (1) ◽  
pp. 107-112 ◽  
Author(s):  
Pavel Lederer ◽  
Galina V. Nizova ◽  
Marina M. Kats ◽  
Georgii B. Shuľpin
Keyword(s):  
Electron Transfer ◽  
Transition Metal ◽  
Molecular Oxygen ◽  
Reaction Pathway ◽  
Oxidation States ◽  
Quantum Yields ◽  
Radiation Wavelength ◽  
Metal Chlorides ◽  
Active Complex ◽  
Oxo Complexes

Irradiation of cyclohexane solution in acetonitrile (λ = 300, 365, or 436 nm) in the presence of dioxygen and catalytic amounts of FeCl3, CuCl3, Na[AuCl4] or H2[PtCl]6 gives rise to cyclohexanol and cyclohexanone (after GLC). The quantum yields with respect to the products lie within the range of 0.01 to 0.05. The most efficient of the catalysts used is FeCl3, and the most efficient radiation wavelength is λ = 365 nm. A reaction pathway is suggested; it is assumed that the first step is photoexcitation of M-Cl followed by electron transfer from the ligand to the metal associated with the formation of the Cl. radical, which reacts (probably after solvation by the solvent) with RH giving R.. The Fe(II) species is oxidized by ROO., and the photocatalytically active complex is restored. Complexes with metals in low oxidation states (particularly in the case of Cu, Au and Pt), however, can react with molecular oxygen to give peroxo or oxo complexes, which can directly hydroxylate alkanes.

scholarly journals Statistical Analysis of C–H Activation by Transition Metal Oxo Species Supports Thermodynamic Control Over Reactivity

2020 ◽  
Author(s):  
Joseph Schneider ◽  
McKenna Goetz ◽  
John Anderson
Keyword(s):  
Statistical Analysis ◽  
Transition Metal ◽  
Density Functional ◽  
Relative Magnitude ◽  
Data Set ◽  
Functional Theory ◽  
Oxo Complexes ◽  
Electronic Parameters ◽  
Reaction Barriers ◽  
Radical Character

Transition metal oxo species are key intermediates for the activation of strong C‒H bonds. As such, there has been interest in understanding which structural or electronic parameters of metal oxo complexes determine their reactivity. Factors such as ground state thermodynamics, spin state, steric environment, oxygen radical character, and asynchronicity have all been cited as key contributors, yet there is no consensus on when each of these parameters is significant or the relative magnitude of their effects. Herein, we present a thorough statistical analysis of parameters that have been proposed to influence transition metal oxo mediated C‒H activation. We used density functional theory (DFT) to compute parameters for transition metal oxo complexes and analyzed their ability to explain and predict an extensive data set of experimentally determined reaction barriers. We found that, in general, only thermodynamic parameters related to the free energy of hydrogen atom, proton, and electron transfer play a statistically significant role.

scholarly journals Statistical Analysis of C–H Activation by Transition Metal Oxo Species Supports Thermodynamic Control Over Reactivity

2020 ◽  
Author(s):  
Joseph Schneider ◽  
McKenna Goetz ◽  
John Anderson
Keyword(s):  
Statistical Analysis ◽  
Transition Metal ◽  
Density Functional ◽  
Relative Magnitude ◽  
Data Set ◽  
Functional Theory ◽  
Oxo Complexes ◽  
Electronic Parameters ◽  
Reaction Barriers ◽  
Radical Character

Transition metal oxo species are key intermediates for the activation of strong C‒H bonds. As such, there has been interest in understanding which structural or electronic parameters of metal oxo complexes determine their reactivity. Factors such as ground state thermodynamics, spin state, steric environment, oxygen radical character, and asynchronicity have all been cited as key contributors, yet there is no consensus on when each of these parameters is significant or the relative magnitude of their effects. Herein, we present a thorough statistical analysis of parameters that have been proposed to influence transition metal oxo mediated C‒H activation. We used density functional theory (DFT) to compute parameters for transition metal oxo complexes and analyzed their ability to explain and predict an extensive data set of experimentally determined reaction barriers. We found that, in general, only thermodynamic parameters related to the free energy of hydrogen atom, proton, and electron transfer play a statistically significant role.

scholarly journals Conversion of Methanol on Rutile TiO2 (110) and Tungsten Oxide Clusters: 2. The Role of Defects and Electron Transfer in Bifunctional Oxidic Photocatalysts

2021 ◽  
Author(s):  
Lars Mohrhusen ◽  
Jessica Kräuter ◽  
Katharina Al-Shamery
Keyword(s):  
Electron Transfer ◽  
Transition Metal ◽  
Metal Oxide ◽  
Tungsten Oxide ◽  
Organic Compounds ◽  
Uv Irradiation ◽  
Organic P ◽  
Rutile Tio2 ◽  
Metal Oxide Surfaces

The photochemical conversion of organic compounds on tailored transition metal oxide surfaces by (UV) irradiation has found wide applications ranging from the production of chemicals to the degradation of organic...

Sign in / Sign up

Export Citation Format

Share Document