Charge-shift bonding

S. Shaik, D. Danovich, B. Silvi, D. Lauvergnat, P. C. Hiberty, Chem. Eur. J. 11, 6358 (2005). Charge-Shift Bonding A Class of Electron-Pair Bonds that Emerges from Valence Bond Theory and Is Supported by the Electron Localization Function Approach. 

Charge-Shift Bonding—A Class of Electron-Pair Bonds that Emerges from Valence Bond Theory and Is Supported by the Electron Localization Function Approach. 

Barriers of Hydrogen vs. Halogen Exchange An Experimental Manifestation of Charge-Shift Bonding. 

Shaik and coworkers have carried out extensive studies of tin bonding by means of a valence bond (VB) approach which results in charge-shift bonds.These bonds are neither ionic nor covalent, but are a resonance mixture of the two forms. This approach has been used to examine hydrogen transfer between X groups, where X = CH3, SiHg, GeHg, SnHg, and with the CCSD(T) and MP2... 

CS, charge shift bond (p. 705) density matrix (p. 6651 electron gas (p. 7061 electronic density (p. 665) electron pair distribution (p. 690)... 

Note Fj is also destabilized by repulsive interactions between lone pairs. Politzer, P. (1969). Anomalous properties of fluorine. J. Am. Chem. Soc., 97(23), 6235-6237. Tt appears rather that the anomaly involves the fluorine atom, in whatever circumstances, and its interaction with an external electron which enters its outer shell. [...] In any case, it is suggested that because of the exceptionally small size of the fluorine atom (see Table I), the entering electron feels unusually large forces of attraction from the nucleus and repulsion from the electrons already associated with the atom. It appears that the magnitude of the anomaly in the repulsive forces is greater than in the attractive forces. For an alternative perspective, see also the Charge-Shift Bond Section. 

This Inverted Bond was Suggested to be a Charge-Shift Bond Wu, W., Gu, J., Song, J., Shaik, S., Hiberty, P. C. (2009). The inverted bond in [l.l.l]propellane is a charge-shift bond. Angewandte Chemie International Edition, 48(S), 1407-1410. 

Charge-Shift Bonding Concept. Electron Pair Bonds with Very Large Resonance Energies. 

Shaik S, Danovich D, Wu W, Hiberty PC (2009) Charge-shift bonding and its manifestations in chemistry. Nat Chem 1 443-449... 

Shaik S, Danovich D, Silvi B, Lauvergnat DL, Hiberty PC (2005) Charge-shift bonding-A class of electron-pair bonds that emerges from valence bond theory and is supported by the electron locahzation function approach. Chem A Eur J 11(21) 6358-6371... 

Shaik S, Maitre P, Sini G, Hiberty PC (1992) The charge-shift bonding concept Electron-parr bonds with very large ionic-covalent resonance energies. J Am Chem Soc 114(20) 7861-7866... 

Jenkins S et al. (2011) The mechanics of charge-shift bonds A perspective from the electronic stress tensor. Chem Phys Lett 510 18-20... 

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