Four-center two-electron bond

Four-center two-electron bond

A four-center two-electron bond is a type of chemical bond in which four atoms share two electrons in bonding which is unusual because in ordinary chemical bonds two atoms share two electrons (2c-2e bonding). This type of bonding is postulated in certain cluster compounds. For instance, the borane B6H7- anion, is a B6H62- octahedron with an additional proton attached to one of the triangular faces. ["A new 4c–2e bond in B6H7–" Kathrin Hofmann, Marc H. Prosenc and Barbara R. Albert Chem. Commun., 2007, 3097 - 3099, DOI|10.1039/b704944g] . As a result the octahedron is distorted and a BBBH rhomboid ring can be identified in which this 4c-2e bonding takes place. This type of bonding is associated with electron deficient rhomboid rings in general ["Electron-Deficient Bonding in Rhomboid Rings"Musiri M. Balakrishnarajan and Roald Hoffmann J. Am. Chem. Soc.; 2004; 126(40) pp 13119 - 13131; (Article) DOI: 10.1021/ja0467420] and is a relatively new research field, fitting in with the already well established three-center two-electron bonds and three-center four-electron bonds.

An example of a purely organic compound with four-center two-electron bonding is the adamantyl dication. [Matthias Bremer, Paul von Ragué Schleyer, Karl Schötz, Michael Kausch, Michael Schindler Four-Center Two-Electron Bonding in a Tetrahedral Topology. Experimental Realization of Three-Dimensional Homoaromaticity in the 1,3-Dehydro-5,7-adamantanediyl Dication. "Angewandte Chemie International Edition in English" 1987, "26", 761-763. doi|10.1002/anie.198707611]

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Three-center two-electron bond — A three center two electron bond is an electron deficient chemical bond where three atoms share two electrons. The combination of three atomic orbitals form three molecular orbitals: one bonding, one non bonding, and one anti bonding. The two… …   Wikipedia

  • Three-center four-electron bond — The 3 center 4 electron bond is a model used to explain bonding in hypervalent molecules such as phosphorus pentafluoride, sulfur hexafluoride, the xenon fluorides, and the hydrogen difluoride ion. [Greenwood Earnshaw p. 897.] [Weinhold, F.;… …   Wikipedia

  • Chemical bond — A chemical bond is an attraction between atoms that allows the formation of chemical substances that contain two or more atoms. The bond is caused by the electromagnetic force attraction between opposite charges, either between electrons and… …   Wikipedia

  • Three-center bond — In chemistry, there are two types of three center bonds: *Three center two electron bond, found in electron deficient compounds such as boranes *Three center four electron bond, found in hypervalent compounds such as the noble gas compounds …   Wikipedia

  • Bond length — In molecular geometry, bond length or bond distance is the average distance between nuclei of two bonded atoms in a molecule. Explanation Bond length is inversely related to bond order, when more electrons participate in bond formation the bond… …   Wikipedia

  • Covalent bond — Covalent redirects here. For other uses, see Covalent (disambiguation). A covalent bond forming H2 (right) where two h …   Wikipedia

  • Hydrogen bond — A hydrogen bond results from a dipole dipole force between an electronegative atom and a hydrogen atom bonded to nitrogen, oxygen or fluorine (thus the name hydrogen bond , which must not be confused with a covalent bond to hydrogen). The energy… …   Wikipedia

  • Symmetric hydrogen bond — A symmetric hydrogen bond is a special type of hydrogen bond in which the proton is spaced exactly halfway between two identical atoms. The strength of the bond to each of those atoms is equal. It is an example of a 3 center 4 electron bond. This …   Wikipedia

  • Electron — For other uses, see Electron (disambiguation). Electron Experiments with a Crookes tube first demonstrated the particle nature of electrons. In this illustration, the profile of the cross shaped target is projected against the tube face at right… …   Wikipedia

  • Borane — In chemistry, a borane is a chemical compound of boron and hydrogen. The boranes comprise a large group of compounds with the generic formulae of BxHy. These compounds do not occur in nature. Many of the boranes readily oxidise on contact with… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”