Bond activation by group-11 transition-metal cations

2009 ◽  
Vol 87 (7) ◽  
pp. 806-817 ◽  
Author(s):  
G. Theodoor de Jong ◽  
F. Matthias Bickelhaupt
Keyword(s):  
Transition Metal ◽  
Density Functional ◽  
Bond Activation ◽  
Chemical Reactivity ◽  
Metal Cations ◽  
Metal Species ◽  
Transition Metal Cations ◽  
Functional Theory ◽  
Reaction Barriers ◽  
Strain Model

We have computationally explored C–X bond activation by the group-11 transition-metal cations Cu+, Ag+, and Au+, and, for comparison, Pd, using relativistic density functional theory (DFT) at ZORA-BLYP/TZ2P. Oxidative insertion of the second-row transition-metal species Ag+ and Pd leads, for a given bond, to the highest overall reaction barriers. On the other hand, if we compare the different bonds oxidative insertion into the C–F bond is associated with (one of the) highest overall barriers whereas insertion into the C–Cl bond leads to the lowest overall barrier for any transition metal. The main trends in reactivity are rationalized using the activation strain model of chemical reactivity, which is an extension of the fragment approach to reaction profiles. In this model, the shape of the reaction profile ΔE(ζ) and the height of the overall reaction barrier ΔE≠ = ΔE(ζ=ζTS) are interpreted in terms of the strain energy ΔEstrain(ζ) associated with deforming the reactants along the reaction coordinate ζ plus the interaction energy ΔEint(ζ) between these deformed reactants: ΔE(ζ) = ΔEstrain(ζ) + ΔEint(ζ).

scholarly journals DFT Study of Unstrained Ketone C-C Bond Activation via Rhodium(I)-Catalyzed Suzuki-Miyaura Cross-Coupling Reactions

2019 ◽  
Author(s):  
Dengmengfei Xiao ◽  
Lili Zhao ◽  
Diego Andrada
Keyword(s):  
Density Functional ◽  
Bond Activation ◽  
Chemical Reactivity ◽  
Cross Coupling ◽  
Underlying Mechanism ◽  
Reductive Elimination ◽  
Coupling Reactions ◽  
Co Catalysts ◽  
Cross Coupling Reactions ◽  
Strain Model

Unstrained cyclic ketones can participate in cooperative Suzuki-Miyaura cross-coupling type reaction using rhodium(I)-based catalyst via C-C bond activation. The regioselectivity indicates a trend where the most substituted side is activated and it is controlled by the beta-substituents. In this work, Density Functional Theory (DFT) calculations have been carried out to disclose the underlying mechanism in the reaction of a ketone series and arylboronate using ylidene as ancillary ligand and pyridine as co-catalysts. The computed energies suggest the reductive elimination step with the highest energy while the reductive elimination has the highest energy barrier. By the means of the Activation Strain Model (ASM) of chemical reactivity, it is found that the ketone strain energy released on the oxidative addition does not control the relativity of the OA reactivity, but indeed is the interaction energy between Rh(I) and C-C bond the ruling effect. The effect of the beta-substituents on regioselectivity has been additionally studied.

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.

Density functional theory based embedding approaches for transition-metal complexes

2020 ◽  
Vol 22 (45) ◽  
pp. 26093-26103
Author(s):  
Moritz Bensberg ◽  
Johannes Neugebauer
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Chemical Reactions ◽  
Density Functional ◽  
Metal Species ◽  
Functional Theory

Density functional theory based embedding approaches for the description of chemical reactions are reviewed for their applicability to transition metal species.

Face selectivity of the C-H bond activation of cyclohexane by the "Bare" first-row transition-metal cations Sc+-Zn+

1995 ◽  
Vol 14 (10) ◽  
pp. 4465-4470 ◽  
Author(s):  
Katrin Seemeyer ◽  
Detlef Schroeder ◽  
Martin Kempf ◽  
Olaf Lettau ◽  
Joern Mueller ◽  
...  
Keyword(s):  
Transition Metal ◽  
Bond Activation ◽  
Metal Cations ◽  
Transition Metal Cations ◽  
Face Selectivity

Density Functional Study of Ammonia Activation by Late First-Row Transition Metal Cations

2004 ◽  
Vol 43 (16) ◽  
pp. 4944-4952 ◽  
Author(s):  
Maria del Carmen Michelini ◽  
Nino Russo ◽  
Emilia Sicilia
Keyword(s):  
Transition Metal ◽  
Density Functional ◽  
Metal Cations ◽  
Functional Study ◽  
Transition Metal Cations ◽  
Density Functional Study
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