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| Content Provider | Springer Nature Link |
|---|---|
| Author | Murray, Jane S. Lane, Pat Politzer, Peter |
| Copyright Year | 2008 |
| Abstract | The term “σ-hole” originally referred to the electron-deficient outer lobe of a half-filled p (or nearly p) orbital involved in forming a covalent bond. If the electron deficiency is sufficient, there can result a region of positive electrostatic potential which can interact attractively (noncovalently) with negative sites on other molecules (σ-hole bonding). The interaction is highly directional, along the extension of the covalent bond giving rise to the σ-hole. σ-Hole bonding has been observed, experimentally and computationally, for many covalently-bonded atoms of Groups V–VII. The positive character of the σ-hole increases in going from the lighter to the heavier (more polarizable) atoms within a Group, and as the remainder of the molecule becomes more electron-withdrawing. In this paper, we show computationally that significantly positive σ-holes, and subsequent noncovalent interactions, can also occur for atoms of Group IV. This observation, together with analogous ones for the molecules (H3C)2SO, (H3C)2SO2 and Cl3PO, demonstrates a need to expand the interpretation of the origins of σ-holes: (1) While the bonding orbital does require considerable p character, in view of the well-established highly directional nature of σ-hole bonding, a sizeable s contribution is not precluded. (2) It is possible for the bonding orbital to be doubly-occupied and forming a coordinate covalent bond. Figure Two views of the calculated electrostatic potential on the 0.001 au molecular surface of SiCl4. Color ranges, in kcal/mole, are: purple, negative; blue, between 0 and 8; green, between 8 and 11; yellow, between 11 and 18; red, more positive than 18. The top view shows three of the four chlorines. In the center is the σ-hole due to the fourth Cl−Si bond, its most positive portion (red) being on the extension of that bond. In the bottom view are visible two of the σ-holes on the silicon. In both views can be seen the σ-holes on the chlorines, on the extensions of the Si−Cl bonds; their most positive portions are green |
| Starting Page | 723 |
| Ending Page | 729 |
| Page Count | 7 |
| File Format | |
| ISSN | 16102940 |
| Journal | Journal of Molecular Modeling |
| Volume Number | 15 |
| Issue Number | 6 |
| e-ISSN | 09485023 |
| Language | English |
| Publisher | Springer-Verlag |
| Publisher Date | 2008-12-11 |
| Publisher Place | Berlin, Heidelberg |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Electrostatic potentials Group IV atoms Noncovalent interactions σ-hole σ-hole bonding Computer Application in Life Sciences Life Sciences Health Informatics Molecular Medicine Biomedicine general Computer Applications in Chemistry |
| Content Type | Text |
| Resource Type | Article |
| Subject | Organic Chemistry Physical and Theoretical Chemistry Computational Theory and Mathematics Catalysis Inorganic Chemistry Computer Science Applications |
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