ChemInform Abstract: Central Bond in the Three CN× Dimers NC‐CN, CN‐CN, and CN‐NC: Electron Pair Bonding and Pauli Repulsion Effects.

Bickelhaupt, F. Matthias; Nibbering, N. M. M.; Wezenbeek, Egbert van; Baerends, E. J.

doi:10.1002/chin.199238047

Cited by 3 publications

(3 citation statements)

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“…It is seen that for all species where both quantities could be determined, the RE CS is larger than the corresponding D e values, thus underscoring the above conclusion that RE CS fully originates from the 3e-bonding, while each structure by itself suffers from Pauli repulsion. A similar conclusion was reached by use of energy decomposition analysis (EDA) 107 of the 3ebond in (H 2 S∴SH 2 ) + . 108 Thus, as was demonstrated by Bickelhaupt et al, 108 the 3e-bond energy is a balance between the Pauli repulsion of the two α-spin electrons located on the two sulfur atoms, while the interaction of the β electron in the H 2 S: lone pair with the vacant β spin orbital on the H 2 S •+ radical cation site takes care of the CS resonance energy.…”

Section: Discussionsupporting

confidence: 69%

Nature of the Three-Electron Bond

et al. 2018

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We analyze the properties of 15 3-electron bonds, which include σ-3-electron-bonds, such as dihalide radical anions and di-noble gas radical cations, π-3-electron-bonds as in hydrazine radical cations, and doubly-π-(3e)-bonded species such as O, FeO, S, etc. The primary analytical tool is the breathing-orbital valence-bond (BOVB) method, which enables us to quantify the charge shift resonance energy (RE) of the three electrons, and the bond dissociation energies (D). BOVB is tested reliable against MRCI calculations. Our findings show that in all 3-electron bonds, none of the VB structures have by themselves any bonding. In fact, in each VB structure, the three electrons maintain Pauli repulsion, while the entire bonding energy arises from resonance due to the charge shift between the two or more constituent VB structures. Hence, 3e-bonds are charge shift bonds (CSBs). The CSB character is probed by calculating the Laplacian (L) of the 3e-bond. Thus, much like the CSBs in electron-pair bonds, such as F or the central bond in [1.1.1]propellane, here too L is positive, thus showing the excess kinetic energy of the shared density due to the Pauli repulsion in the 3-electron VB structures. The RE values for 3-electron bonds are invariably larger than the corresponding bond energies. For the doubly-π-(3e)-bonded species, RE is very large, exceeding 100 kcal mol. As such, it is fitting to conclude that σ- and π-3-electron-bonds find their natural place in the CSB family along with two-electron CSBs, with which they share identical energetic and topological characteristics. Experimental manifestations/tests of 3e-CSBs are proposed.

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Section: Discussionsupporting

confidence: 69%

Nature of the Three-Electron Bond

et al. 2018

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“…The orbital interaction ΔE orb accounts for charge transfer, polarization effects, and electron-pair bonding. 78 In the case that the Grimme dispersion corrections 79,80 are computed the term ΔE disp is added to the equation to count the dispersion interaction between the fragments.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Synthesis, Structure, and Bonding Analysis of Tin(II) Dihalide and Cyclopentadienyltin(II) Halide (Alkyl)(amino)carbene Complexes

et al. 2019

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Tin(II) dibromide, 2b, and cyclopentadienyltin(II) chloride, 2c, and cyclopentadienyltin(II) bromide, 2d, were reacted with cyclic (alkyl)(amino)carbene (cAAC), 1, to give the corresponding complexes cAAC·SnBr2, 3b, cAAC·SnCpCl, 3c, and cAAC·SnCpBr, 3d, which were studied in solution and in the solid state. Although isolatable as crystalline solids, 3c,d exist in a heteroleptic/homoleptic equilibrium with other tin(II) species, in solution. In addition, the coordination chemistry of 3b was investigated and the corresponding iron tetracarbonyl complex, 5, could be isolated and structurally characterized. Furthermore, the mechanism of the equilibrium reaction observed for 3c,d in solution, as well as the chemical bonding nature of all cAAC complexes were investigated by quantum-chemical calculations within the DFT framework.

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“…General theoretical background on the bond energy decomposition scheme used here (Morokuma-Ziegler) can be found in the papers by Bickelhaupt and Baerends [39,41]. Finally, in the EDA of the bonding energy, open-shell fragments were treated with the spin-unrestricted formalism, but for technical reasons, spin polarization cannot be included.…”

Section: Energy Decomposition Analysismentioning

confidence: 99%

Why 1,2-quinone derivatives are more stable than their 2,3-analogues?

et al. 2015

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In this work, we have studied the relative stability of 1,2- and 2,3-quinones. While 1,2-quinones have a closed-shell singlet ground state, the ground state for the studied 2,3-isomers is open-shell singlet, except for 2,3-naphthaquinone that has a closed-shell singlet ground state. In all cases, 1,2-quinones are more stable than their 2,3-counterparts. We analyzed the reasons for the higher stability of the 1,2-isomers through energy decomposition analysis in the framework of Kohn–Sham molecular orbital theory. The results showed that we have to trace the origin of 1,2-quinones’ enhanced stability to the more efficient bonding in the π-electron system due to more favorable overlap between the SOMOπ of the ·C4n−2H2n–CH·· and ··CH–CO–CO· fragments in the 1,2-arrangement. Furthermore, whereas 1,2-quinones present a constant trend with their elongation for all analyzed properties (geometric, energetic, and electronic), 2,3-quinone derivatives present a substantial breaking in monotonicityThis work has been supported by the European Union in the framework of European Social Fund through the Warsaw University of Technology Development Programme. O.A. S., H. S. and T.M. K. gratefully acknowledge the Foundation for Polish Science for supporting this work under MPD/2010/4 project "Towards Advanced Functional Materials and Novel Devices-Joint UW and WUT International PhD Programme" and the Interdisciplinary Center for Mathematical and Computational Modeling (Warsaw, Poland) for providing computer time and facilities. Thanks are also to the Ministerio de Economia y Competitividad of Spain (Projects CTQ2011-23156/BQU and CTQ2011-25086) and the Generalitat de Catalunya (project numbers 2014SGR931, Xarxa de Referencia en Quimica Teorica i Computacional, and ICREA Academia 2014 prize for MS

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ChemInform Abstract: Central Bond in the Three CN× Dimers NC‐CN, CN‐CN, and CN‐NC: Electron Pair Bonding and Pauli Repulsion Effects.

Cited by 3 publications

References 1 publication

Nature of the Three-Electron Bond

Nature of the Three-Electron Bond

Synthesis, Structure, and Bonding Analysis of Tin(II) Dihalide and Cyclopentadienyltin(II) Halide (Alkyl)(amino)carbene Complexes

Why 1,2-quinone derivatives are more stable than their 2,3-analogues?

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