Chemical bonding in hypervalent molecules. The dominance of ionic bonding and negative hyperconjugation over d-orbital participation

1990 ◽  
Vol 112 (4) ◽  
pp. 1434-1445 ◽  
Author(s):  
Alan E. Reed ◽  
Paul v. R. Schleyer
Keyword(s):  
Chemical Bonding ◽  
Ionic Bonding ◽  
Negative Hyperconjugation ◽  
Hypervalent Molecules

scholarly journals Teaching of chemical bonding: a study of Swedish and South African students' conceptions of bonding

2016 ◽  
Vol 17 (4) ◽  
pp. 985-1005 ◽  
Author(s):  
Anders Nimmermark ◽  
Lars Öhrström ◽  
Jerker Mårtensson ◽  
Bette Davidowitz
Keyword(s):  
Secondary School ◽  
South African ◽  
Chemical Bonding ◽  
School Level ◽  
Upper Secondary School ◽  
African Students ◽  
Counter Measures ◽  
Ionic Bonding ◽  
Upper Secondary ◽  
Endothermic Reactions

Almost 700 Swedish and South African students from the upper secondary school and first-term chemistry university level responded to our survey on concepts of chemical bonding. The national secondary school curricula and most common textbooks for both countries were also surveyed and compared for their content on chemical bonding. Notable differences between the countries were found in textbooks and in the curriculum regarding the topics of ionic bonding, bond energetics and use of the VSEPR model, the latter being absent in the Swedish curriculum and ionic bonding not explicitly mentioned in the South African curriculum. To some extent these differences are reflected in the students’ responses to the survey. It is also clear that university teachers in both countries must prepare effective counter-measures against deep rooted misunderstandings. For the upper secondary school level it is suggested that the bond energetics and exothermic and endothermic reactions be clearly and carefully presented and separated as the study indicates that mixing of these two concepts is a major cause of confusion.

Chemical Bonding in Hypervalent Molecules:  Is the Octet Rule Relevant?

2002 ◽  
Vol 41 (8) ◽  
pp. 2164-2172 ◽  
Author(s):  
Stéphane Noury ◽  
Bernard Silvi ◽  
Ronald J. Gillespie
Keyword(s):  
Chemical Bonding ◽  
Hypervalent Molecules ◽  
Octet Rule

Calculation of Compton Profiles Using the DV-Xα Method for 14 Electron Diatomic Molecules

2011 ◽  
Vol 497 ◽  
pp. 19-25 ◽  
Author(s):  
Kohjiro Kobayashi ◽  
Hiroshi Sakurai
Keyword(s):  
Configuration Interaction ◽  
Chemical Bonding ◽  
Diatomic Molecules ◽  
Covalent Bonding ◽  
Ionic Bonding ◽  
Hartree Fock

Isotropic and directional Compton profiles are calculated for 14 electron diatomic molecules, N2, CO, and BF, using the DV-Xα method. In order to investigate the effect of chemical bonding for Compton profiles, parallel and perpendicular directional Compton profiles to the molecules are calculated and compared with the results from Hartree-Fock and configuration interaction methods. The DV-Xα method could describe the more detailed character of covalent bonding than that of ionic bonding.

On Drago's E-C Equation, Pearson's HSAB Rule and the Ionic Approximation to Chemical Bonding

1975 ◽  
Vol 30 (2) ◽  
pp. 223-226 ◽  
Author(s):  
G. Van Hooydonk
Keyword(s):  
Electron Affinity ◽  
Chemical Bonding ◽  
Bond Energy ◽  
Energy Equation ◽  
Ionic Species ◽  
Ionic Interactions ◽  
Ionic Bonding ◽  
Interacting Species ◽  
First Approximation ◽  
Chemical Behaviour

Abstract An attempt is made to explain the E-C formalism for ionic interactions in terms of the ionic approximation to chemical bonding. Dravo's E-C equation is seen to be a first approximation to the bond energy equation as it is given by the ionic bonding approach. The meaning of the ratio C/E is discussed and its relation with the hardness and softness of interacting species, as these occur in Pearson's HSAB rule, shows that the electron affinity or electronegativity of elements completely determines the chemical behaviour of ionic species. This analysis illustrates the consistency of the ionic approximation to chemical bonding.

Localized-orbital locator (LOL) profiles of chemical bonding

2008 ◽  
Vol 86 (7) ◽  
pp. 695-702 ◽  
Author(s):  
Heiko Jacobsen
Keyword(s):  
Energy Density ◽  
Kinetic Energy ◽  
Transition Metal Complexes ◽  
Chemical Bonding ◽  
Electron Pair ◽  
Kinetic Energy Density ◽  
Triple Bonds ◽  
Core Electrons ◽  
Localized Orbital ◽  
Hypervalent Molecules

We examine a recently introduced descriptor of chemical bonding, the localized-orbital locator (LOL), which is based on the kinetic-energy density (τ). Examples are presented for prototypical chemical bonds, such as single, double, and triple bonds, for bonding in transition metal complexes, for three-center two-electron bonds, as well as for hypervalent molecules. The topology of LOL is analyzed in terms of (3,–3) attractors (Γ). The influence of core electrons for chemical bonding is investigated, and a LOL-VSEPR (valence shell electron pair repulstion) relationship is established. Further, we compare LOL to the related electron localization function (ELF).Key words: chemical bonding, kinetic-energy density, localized-electron locator, VSEPR theory.

Radiation-induced surface decomposition

1983 ◽  
Vol 41 ◽  
pp. 368-369
Author(s):  
M. L. Knotek
Keyword(s):  
Ionizing Radiation ◽  
Atomic Structure ◽  
Chemical Bonding ◽  
Neutral Species ◽  
Radiation Induced ◽  
Physical And Chemical ◽  
Surface Decomposition ◽  
The Relationship ◽  
Electron And Photon ◽  
Surface Bond

Modern surface analysis is based largely upon the use of ionizing radiation to probe the electronic and atomic structure of the surfaces physical and chemical makeup. In many of these studies the ionizing radiation used as the primary probe is found to induce changes in the structure and makeup of the surface, especially when electrons are employed. A number of techniques employ the phenomenon of radiation induced desorption as a means of probing the nature of the surface bond. These include Electron- and Photon-Stimulated Desorption (ESD and PSD) which measure desorbed ionic and neutral species as they leave the surface after the surface has been excited by some incident ionizing particle. There has recently been a great deal of activity in determining the relationship between the nature of chemical bonding and its susceptibility to radiation damage.

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