Editing Van der Waals force (section)

==London dispersion force==
{{Main|London dispersion force}}

[[London dispersion force]]s, named after the German-American physicist [[Fritz London]], are weak [[intermolecular force]]s that arise from the interactive forces between instantaneous multipoles in molecules without permanent [[Multipole expansion|multipole moments]]. In and between organic molecules the multitude of contacts can lead to larger contribution of dispersive attraction, particularly in the presence of heteroatoms. London dispersion forces are also known as '[[London dispersion force|dispersion]] forces', 'London forces', or 'instantaneous dipole–induced dipole forces'. The strength of London dispersion forces is proportional to the polarizability of the molecule, which in turn depends on the total number of electrons and the area over which they are spread. Hydrocarbons display small dispersive contributions, the presence of heteroatoms lead to increased LD forces as function of their polarizability, e.g. in the sequence RI>RBr>RCl>RF.<ref>{{Cite journal | doi=10.1021/acs.accounts.5b00111| title=Dispersive Interactions in Solution Complexes| year=2015| last1=Schneider| first1=Hans-Jörg| journal=Accounts of Chemical Research| volume=48| issue=7| pages=1815–1822| pmid=26083908}}</ref> In absence of solvents weakly polarizable hydrocarbons form crystals due to dispersive forces; their [[Sublimation (chemistry)|sublimation heat]] is a measure of the dispersive interaction.