scholarly journals Cobalt-catalyzed C–H cyanations: Insights into the reaction mechanism and the role of London dispersion

2018 ◽  
Vol 14 ◽  
pp. 1537-1545 ◽  
Author(s):  
Eric Detmar ◽  
Valentin Müller ◽  
Daniel Zell ◽  
Lutz Ackermann ◽  
Martin Breugst
Keyword(s):  
Reaction Mechanism ◽  
Density Functional ◽  
Decomposition Analysis ◽  
Energy Decomposition Analysis ◽  
Local Energy ◽  
Energy Decomposition ◽  
Functional Theory ◽  
London Dispersion ◽  
Cobalt Center

Carboxylate-assisted cobalt(III)-catalyzed C–H cyanations are highly efficient processes for the synthesis of (hetero)aromatic nitriles. We have now analyzed the cyanation of differently substituted 2-phenylpyridines in detail computationally by density functional theory and also experimentally. Based on our investigations, we propose a plausible reaction mechanism for this transformation that is in line with the experimental observations. Additional calculations, including NCIPLOT, dispersion interaction densities, and local energy decomposition analysis, for the model cyanation of 2-phenylpyridine furthermore highlight that London dispersion is an important factor that enables this challenging C–H transformation. Nonbonding interactions between the Cp* ligand and aromatic and C–H-rich fragments of other ligands at the cobalt center significantly contribute to a stabilization of cobalt intermediates and transition states.

scholarly journals Direct estimate of the internal π-donation to the carbene centre within N-heterocyclic carbenes and related molecules

2015 ◽  
Vol 11 ◽  
pp. 2727-2736 ◽  
Author(s):  
Diego M Andrada ◽  
Nicole Holzmann ◽  
Thomas Hamadi ◽  
Gernot Frenking
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Decomposition Analysis ◽  
Heterocyclic Carbenes ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Direct Estimate ◽  
Functional Theory ◽  
Bonding Analysis

Fifteen cyclic and acylic carbenes have been calculated with density functional theory at the BP86/def2-TZVPP level. The strength of the internal X→p(π) π-donation of heteroatoms and carbon which are bonded to the C(II) atom is estimated with the help of NBO calculations and with an energy decomposition analysis. The investigated molecules include N-heterocyclic carbenes (NHCs), the cyclic alkyl(amino)carbene (cAAC), mesoionic carbenes and ylide-stabilized carbenes. The bonding analysis suggests that the carbene centre in cAAC and in diamidocarbene have the weakest X→p(π) π-donation while mesoionic carbenes possess the strongest π-donation.

scholarly journals Correction: New light on an old debate: does the RCN–PtCl2 bond include any back-donation? RCN ← PtCl2 backbonding vs. the IR νCN blue-shift dichotomy in organonitriles–platinum(ii) complexes. A thorough density functional theory – energy decomposition analysis study

2019 ◽  
Vol 48 (35) ◽  
pp. 13491-13492 ◽  
Author(s):  
Girolamo Casella ◽  
Célia Fonseca Guerra ◽  
Silvia Carlotto ◽  
Paolo Sgarbossa ◽  
Roberta Bertani ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Decomposition Analysis ◽  
Blue Shift ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Functional Theory ◽  
Dalton Trans ◽  
Analysis Study ◽  
Back Donation

Correction for ‘New light on an old debate: does the RCN–PtCl2 bond include any back-donation? RCN ← PtCl2 backbonding vs. the IR νCN blue-shift dichotomy in organonitriles–platinum(ii) complexes. A thorough density functional theory – energy decomposition analysis study’ by Girolamo Casella et al., Dalton Trans., 2019, DOI: 10.1039/c9dt02440a.

scholarly journals Local energy decomposition analysis of hydrogen-bonded dimers within a domain-based pair natural orbital coupled cluster study

2018 ◽  
Vol 14 ◽  
pp. 919-929 ◽  
Author(s):  
Ahmet Altun ◽  
Frank Neese ◽  
Giovanni Bistoni
Keyword(s):  
Hydrogen Fluoride ◽  
Decomposition Analysis ◽  
Energy Decomposition Analysis ◽  
Intermolecular Distance ◽  
Local Energy ◽  
Natural Orbital ◽  
Energy Decomposition ◽  
Potential Wells ◽  
Dynamic Charge ◽  
London Dispersion

The local energy decomposition (LED) analysis allows for a decomposition of the accurate domain-based local pair natural orbital CCSD(T) [DLPNO-CCSD(T)] energy into physically meaningful contributions including geometric and electronic preparation, electrostatic interaction, interfragment exchange, dynamic charge polarization, and London dispersion terms. Herein, this technique is employed in the study of hydrogen-bonding interactions in a series of conformers of water and hydrogen fluoride dimers. Initially, DLPNO-CCSD(T) dissociation energies for the most stable conformers are computed and compared with available experimental data. Afterwards, the decay of the LED terms with the intermolecular distance (r) is discussed and results are compared with the ones obtained from the popular symmetry adapted perturbation theory (SAPT). It is found that, as expected, electrostatic contributions slowly decay for increasing r and dominate the interaction energies in the long range. London dispersion contributions decay as expected, as r −6. They significantly affect the depths of the potential wells. The interfragment exchange provides a further stabilizing contribution that decays exponentially with the intermolecular distance. This information is used to rationalize the trend of stability of various conformers of the water and hydrogen fluoride dimers.

scholarly journals From Intermolecular Interaction Energies and Observable Shifts to Component Contributions and Back Again: A Tale of Variational Energy Decomposition Analysis

2021 ◽  
Vol 72 (1) ◽  
pp. 641-666
Author(s):  
Yuezhi Mao ◽  
Matthias Loipersberger ◽  
Paul R. Horn ◽  
Akshaya Das ◽  
Omar Demerdash ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Intermolecular Interaction ◽  
Density Functional ◽  
Decomposition Analysis ◽  
Radical Cations ◽  
Energy Decomposition Analysis ◽  
Interaction Energies ◽  
Energy Decomposition ◽  
Functional Theory ◽  
Pauli Repulsion

Quantum chemistry in the form of density functional theory (DFT) calculations is a powerful numerical experiment for predicting intermolecular interaction energies. However, no chemical insight is gained in this way beyond predictions of observables. Energy decomposition analysis (EDA) can quantitatively bridge this gap by providing values for the chemical drivers of the interactions, such as permanent electrostatics, Pauli repulsion, dispersion, and charge transfer. These energetic contributions are identified by performing DFT calculations with constraints that disable components of the interaction. This review describes the second-generation version of the absolutely localized molecular orbital EDA (ALMO-EDA-II). The effects of different physical contributions on changes in observables such as structure and vibrational frequencies upon complex formation are characterized via the adiabatic EDA. Example applications include red- versus blue-shifting hydrogen bonds; the bonding and frequency shifts of CO, N2, and BF bound to a [Ru(II)(NH3)5]2 + moiety; and the nature of the strongly bound complexes between pyridine and the benzene and naphthalene radical cations. Additionally, the use of ALMO-EDA-II to benchmark and guide the development of advanced force fields for molecular simulation is illustrated with the recent, very promising, MB-UCB potential.

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