London force
London forces (after the physicist Fritz London ; in literature also called London force , London dispersion or attractive van der Waals bond ) are weak forces of attraction between polar or non-polar molecules and atoms , which are caused by spontaneous polarization of a particle and this creates induced dipoles in neighboring particles. In quantum mechanics , such interactions can be modeled as a force field that decreases with the sixth power of the distance:
The London Forces explain the existence of liquid and solid aggregate states of non-polar compounds, which should not exist if one only considers the repulsive interaction of their electron shells (in the absence of other intermolecular interactions such as hydrogen bonds ) . The London forces between non-polar, uncharged particles are much weaker than the other types of bond . In computational chemistry , they are difficult to describe and parameterize. The shares of London's dispersion forces in the forces of attraction between polar molecules are usually stronger than the contributions of the dipole-dipole interaction . Together with Debye 's forces (interaction between permanent dipole molecules and non-polar particles), these belong to the van der Waals interactions .
Individual evidence
- ^ R. Eisenschitz and F. London, Z. Physik 60 , 491 (1930), DOI: 10.1007 / BF01341258 .
- ↑ F. London, Z. Physik 63 , 245 (1930), DOI: 10.1007 / bf01421741 and Z. Physik. Chemistry, B11 , 222 (1930)
- ↑ TL Brown, HE LeMay, BE Bursten, Chemistry - The Central Science, 10th Edition, Pearson Studium, Munich, Boston, 2007, p. 519.
- ↑ TL Brown, HE LeMay, BE Bursten, Chemistry - The Central Science, 10th Edition, Pearson Studium, Munich, Boston, 2007, p. 519.