Intermolecular force: Difference between revisions
Jump to navigation
Jump to search
imported>Orenburg1 m sp |
imported>Sct72 mNo edit summary |
||
| Line 1: | Line 1: | ||
{{short description|Force of attraction or repulsion between molecules and neighboring particles}} | {{short description|Force of attraction or repulsion between molecules and neighboring particles}} | ||
[[File:3D model hydrogen bonds in water.svg|thumb|3D model of [[Hydrogen bond|hydrogen bonding]] between [[water]] molecules, an example of | [[File:3D model hydrogen bonds in water.svg|thumb|3D model of [[Hydrogen bond|hydrogen bonding]] between [[water]] molecules, an example of intermolecular force]] | ||
An '''intermolecular force''' ('''IMF'''; also '''secondary force''') is the force that mediates interaction between [[Molecule|molecules]], including the [[Electromagnetism|electromagnetic forces of attraction | An '''intermolecular force''' ('''IMF'''; also '''secondary force''') is the force that mediates interaction between [[Molecule|molecules]], including the [[Electromagnetism|electromagnetic forces of attraction | ||
or repulsion]] which act between atoms and other types of neighbouring particles (e.g. [[atom]]s or [[ion]]s). Intermolecular forces are weak relative to [[intramolecular force]]s – the forces which hold a molecule together. For example, the [[covalent bond]], involving sharing electron pairs between atoms, is much stronger than the forces present between neighboring molecules.<ref>{{Cite journal |last1=Fischer |first1=Johann |last2=Wendland |first2=Martin |date=October 2023 |title=On the history of key empirical intermolecular potentials |journal=Fluid Phase Equilibria |language=en |volume=573 |article-number=113876 |doi=10.1016/j.fluid.2023.113876|bibcode=2023FlPEq.57313876F |doi-access=free }}</ref> Both sets of forces are essential parts of [[Force field (chemistry)|force fields]] frequently used in [[molecular mechanics]]. | or repulsion]] which act between atoms and other types of neighbouring particles (e.g. [[atom]]s or [[ion]]s). Intermolecular forces are weak relative to [[intramolecular force]]s – the forces which hold a molecule together. For example, the [[covalent bond]], involving sharing electron pairs between atoms, is much stronger than the forces present between neighboring molecules.<ref name="auto">{{Cite journal |last1=Fischer |first1=Johann |last2=Wendland |first2=Martin |date=October 2023 |title=On the history of key empirical intermolecular potentials |journal=Fluid Phase Equilibria |language=en |volume=573 |article-number=113876 |doi=10.1016/j.fluid.2023.113876|bibcode=2023FlPEq.57313876F |doi-access=free }}</ref> Both sets of forces are essential parts of [[Force field (chemistry)|force fields]] frequently used in [[molecular mechanics]]. | ||
The first reference to the nature of microscopic forces is found in [[Alexis Clairaut]]'s work ''Théorie de la figure de la Terre,'' published in Paris in 1743.<ref>{{cite book | vauthors = Margenau H, Kestner NR | title=Theory of Intermolecular Forces |date=1969 |publisher=Pergamon Press |location=Oxford |isbn=978-0-08-016502-8 |edition=1st | series = International Series of Monographs in Natural Philosophy | volume = 18 }}</ref> Other scientists who have contributed to the investigation of microscopic forces include: [[Pierre-Simon Laplace|Laplace]], [[Carl Friedrich Gauss|Gauss]], [[James Clerk Maxwell|Maxwell]], [[Ludwig Boltzmann|Boltzmann]] and [[Linus Pauling|Pauling]]. | The first reference to the nature of microscopic forces is found in [[Alexis Clairaut]]'s work ''Théorie de la figure de la Terre,'' published in Paris in 1743.<ref>{{cite book | vauthors = Margenau H, Kestner NR | title=Theory of Intermolecular Forces |date=1969 |publisher=Pergamon Press |location=Oxford |isbn=978-0-08-016502-8 |edition=1st | series = International Series of Monographs in Natural Philosophy | volume = 18 }}</ref> Other scientists who have contributed to the investigation of microscopic forces include: [[Pierre-Simon Laplace|Laplace]], [[Carl Friedrich Gauss|Gauss]], [[James Clerk Maxwell|Maxwell]], [[Ludwig Boltzmann|Boltzmann]] and [[Linus Pauling|Pauling]]. | ||
| Line 9: | Line 9: | ||
Attractive intermolecular forces are categorized into the following types: | Attractive intermolecular forces are categorized into the following types: | ||
*[[Hydrogen bond]]ing | *[[Hydrogen bond]]ing | ||
*Ion–dipole forces and ion–induced dipole force | *[[Intermolecular force#Ion–dipole and ion–induced dipole forces|Ion–dipole forces and ion–induced dipole force]] | ||
*[[Cation–π interaction|Cation–π]], σ–π and π–π bonding | *[[Cation–π interaction|Cation–π]], σ–π and π–π bonding | ||
*[[Van der Waals force]]s – [[Keesom force]], [[Debye force]], and [[London dispersion force]] | *[[Van der Waals force]]s – [[Keesom force]], [[Debye force]], and [[London dispersion force]] | ||
| Line 65: | Line 65: | ||
:<math>\frac{-d_1^2 d_2^2}{24\pi^2 \varepsilon_0^2 \varepsilon_r^2 k_\text{B} T r^6} = V,</math> | :<math>\frac{-d_1^2 d_2^2}{24\pi^2 \varepsilon_0^2 \varepsilon_r^2 k_\text{B} T r^6} = V,</math> | ||
where ''d'' = | where ''d'' = diameter (atoms), <math>\varepsilon_0</math> = permittivity of free space, <math>\varepsilon_r</math> = dielectric constant of surrounding material, ''T'' = temperature, <math>k_\text{B}</math> = Boltzmann constant, and ''r'' = radius of atom(s). | ||
===Debye force (permanent dipoles–induced dipoles) {{Anchor|Debye force}}=== | ===Debye force (permanent dipoles–induced dipoles) {{Anchor|Debye force}}=== | ||
| Line 95: | Line 95: | ||
|- | |- | ||
|Ionic lattice | |Ionic lattice | ||
| | |30-145 | ||
|127-610 <ref>Calculated on the basis of energy required to release 1 mole of atoms. i.e. the lattice enthalpy minus the ionisation energies and electron affinities e.g. <sup>1</sup>/<sub>5</sub> Al<sub>2</sub>O<sub>3</sub>(s) → <sup>2</sup>/<sub>5</sub> Al(g) + <sup>3</sup>/<sub>5</sub> O(g) 610 kJ/mol</ref> | |||
| | | | ||
|- | |- | ||
|Covalent bond | |Covalent bond | ||
| | |8–170 | ||
| | |33-715<ref>Calculated on the basis of energy required to release 1 mole of atoms. e.g. Kr-F bond in KrF<sub>2</sub> is 50 kJ/mol, and 3 atoms are released by breaking the 2 Kr-F bonds.</ref> | ||
| | |||
|- | |||
|Covalent bond | |||
|14–203 | |||
|60-850<ref>The enthalpy of atomisation for metals. e.g. W(s) → W(g) 850 kJ/mol</ref> | |||
| | | | ||
|- | |- | ||
| Line 124: | Line 129: | ||
==Effect on the behavior of gases== | ==Effect on the behavior of gases== | ||
Intermolecular forces are repulsive at short distances and attractive at long distances (see the [[Lennard-Jones potential]]).<ref | Intermolecular forces are repulsive at short distances and attractive at long distances (see the [[Lennard-Jones potential]]).<ref name="auto"/><ref>{{Cite journal |last1=Lenhard |first1=Johannes |last2=Stephan |first2=Simon |last3=Hasse |first3=Hans |date=June 2024 |title=On the History of the Lennard-Jones Potential |journal=Annalen der Physik |language=en |volume=536 |issue=6 |doi=10.1002/andp.202400115 |issn=0003-3804|doi-access=free }}</ref> In a gas, the repulsive force chiefly has the effect of keeping two molecules from occupying the same volume. This gives a [[real gas]] a tendency to occupy a larger volume than an [[ideal gas]] at the same temperature and pressure. The attractive force draws molecules closer together and gives a real gas a tendency to occupy a smaller volume than an ideal gas. Which interaction is more important depends on temperature and pressure (see [[compressibility factor]]). | ||
In a gas, the distances between molecules are generally large, so intermolecular forces have only a small effect. The attractive force is not overcome by the repulsive force, but by the [[thermal energy]] of the molecules. [[Thermodynamic temperature|Temperature]] is the measure of thermal energy, so increasing temperature reduces the influence of the attractive force. In contrast, the influence of the repulsive force is essentially unaffected by temperature. | In a gas, the distances between molecules are generally large, so intermolecular forces have only a small effect. The attractive force is not overcome by the repulsive force, but by the [[thermal energy]] of the molecules. [[Thermodynamic temperature|Temperature]] is the measure of thermal energy, so increasing temperature reduces the influence of the attractive force. In contrast, the influence of the repulsive force is essentially unaffected by temperature. | ||
| Line 134: | Line 139: | ||
{{Main|Covalent bond#Quantum mechanical description}} | {{Main|Covalent bond#Quantum mechanical description}} | ||
Intermolecular forces observed between atoms and molecules can be described phenomenologically as occurring between permanent and instantaneous dipoles, as outlined above. Alternatively, one may seek a fundamental, unifying theory that is able to explain the various types of interactions such as [[hydrogen bonding]],<ref name=":0">{{Cite journal| vauthors = Arunan E, Desiraju GR, Klein RA, Sadlej J, Scheiner S, Alkorta I, Clary DC, Crabtree RH, Dannenberg JJ, Hobza P, Kjaergaard HG | display-authors = 6 |date=2011-07-08|title=Definition of the hydrogen bond (IUPAC Recommendations 2011)|journal=Pure and Applied Chemistry|volume=83|issue=8|pages=1637–1641|doi=10.1351/PAC-REC-10-01-02|s2cid=97688573|issn=1365-3075|doi-access=free}}</ref> [[van der Waals force]]<ref name=LD>{{cite book | vauthors = Landau LD, Lifshitz EM | title = Electrodynamics of Continuous Media | url = https://archive.org/details/electrodynamicso00land | url-access = registration | publisher = Pergamon | location = Oxford | date = 1960 | pages = [https://archive.org/details/electrodynamicso00land/page/368 368–376] }}</ref> and dipole–dipole interactions. Typically, this is done by applying the ideas of [[quantum mechanics]] to molecules, and Rayleigh–Schrödinger [[perturbation theory]] has been especially effective in this regard. When applied to existing [[quantum chemistry]] methods, such a quantum mechanical explanation of intermolecular interactions provides an array of approximate methods that can be used to analyze intermolecular interactions.<ref>{{cite journal | doi = 10.1021/ja00428a004 | title = Theory of the Chemical Bond | year = 1976 | vauthors = King M | journal = Journal of the American Chemical Society | volume = 98 | issue = 12 | pages = 3415–3420 }}</ref> One of the most helpful methods to visualize this kind of intermolecular interactions, that we can find in quantum chemistry, is the [[Non-covalent interactions index|non-covalent interaction index]], which is based on the electron density of the system. London dispersion forces play a big role with this. | Intermolecular forces observed between atoms and molecules can be described phenomenologically as occurring between permanent and instantaneous dipoles, as outlined above. Alternatively, one may seek a fundamental, unifying theory that is able to explain the various types of interactions such as [[hydrogen bonding]],<ref name=":0">{{Cite journal| vauthors = Arunan E, Desiraju GR, Klein RA, Sadlej J, Scheiner S, Alkorta I, Clary DC, Crabtree RH, Dannenberg JJ, Hobza P, Kjaergaard HG | display-authors = 6 |date=2011-07-08|title=Definition of the hydrogen bond (IUPAC Recommendations 2011)|journal=Pure and Applied Chemistry|volume=83|issue=8|pages=1637–1641|doi=10.1351/PAC-REC-10-01-02|s2cid=97688573|issn=1365-3075|doi-access=free|hdl=11104/0218602|hdl-access=free}}</ref> [[van der Waals force]]<ref name=LD>{{cite book | vauthors = Landau LD, Lifshitz EM | title = Electrodynamics of Continuous Media | url = https://archive.org/details/electrodynamicso00land | url-access = registration | publisher = Pergamon | location = Oxford | date = 1960 | pages = [https://archive.org/details/electrodynamicso00land/page/368 368–376] }}</ref> and dipole–dipole interactions. Typically, this is done by applying the ideas of [[quantum mechanics]] to molecules, and Rayleigh–Schrödinger [[perturbation theory]] has been especially effective in this regard. When applied to existing [[quantum chemistry]] methods, such a quantum mechanical explanation of intermolecular interactions provides an array of approximate methods that can be used to analyze intermolecular interactions.<ref>{{cite journal | doi = 10.1021/ja00428a004 | title = Theory of the Chemical Bond | year = 1976 | vauthors = King M | journal = Journal of the American Chemical Society | volume = 98 | issue = 12 | pages = 3415–3420 }}</ref> One of the most helpful methods to visualize this kind of intermolecular interactions, that we can find in quantum chemistry, is the [[Non-covalent interactions index|non-covalent interaction index]], which is based on the electron density of the system. London dispersion forces play a big role with this. | ||
Concerning electron density topology, recent methods based on electron density gradient methods have emerged recently, notably with the development of IBSI (Intrinsic Bond Strength Index),<ref>{{cite journal | vauthors = Klein J, Khartabil H, Boisson JC, Contreras-García J, Piquemal JP, Hénon E | title = New Way for Probing Bond Strength | journal = The Journal of Physical Chemistry A | volume = 124 | issue = 9 | pages = 1850–1860 | date = March 2020 | pmid = 32039597 | doi = 10.1021/acs.jpca.9b09845 | s2cid = 211070812 | bibcode = 2020JPCA..124.1850K | url = https://hal.archives-ouvertes.fr/hal-02377737/file/4_IGM_bond13012020_11h49%20%281%29.pdf }}</ref> relying on the IGM (Independent Gradient Model) methodology.<ref>{{cite journal | vauthors = Lefebvre C, Rubez G, Khartabil H, Boisson JC, Contreras-García J, Hénon E | title = Accurately extracting the signature of intermolecular interactions present in the NCI plot of the reduced density gradient versus electron density | journal = Physical Chemistry Chemical Physics | volume = 19 | issue = 27 | pages = 17928–17936 | date = July 2017 | pmid = 28664951 | doi = 10.1039/C7CP02110K | bibcode = 2017PCCP...1917928L | url = https://hal.univ-reims.fr/hal-02505160/file/2017_IGM_PROMOL%20%281%29.pdf }}</ref><ref>{{cite journal | vauthors = Lefebvre C, Khartabil H, Boisson JC, Contreras-García J, Piquemal JP, Hénon E | title = The Independent Gradient Model: A New Approach for Probing Strong and Weak Interactions in Molecules from Wave Function Calculations | journal = ChemPhysChem | volume = 19 | issue = 6 | pages = 724–735 | date = March 2018 | pmid = 29250908 | doi = 10.1002/cphc.201701325 | url = https://hal.univ-reims.fr/hal-03377532/file/37_version.pdf }}</ref><ref>{{cite journal | vauthors = Ponce-Vargas M, Lefebvre C, Boisson JC, Hénon E | title = Atomic Decomposition Scheme of Noncovalent Interactions Applied to Host-Guest Assemblies | journal = Journal of Chemical Information and Modeling | volume = 60 | issue = 1 | pages = 268–278 | date = January 2020 | pmid = 31877034 | doi = 10.1021/acs.jcim.9b01016 | s2cid = 209488458 }}</ref> | Concerning electron density topology, recent methods based on electron density gradient methods have emerged recently, notably with the development of IBSI (Intrinsic Bond Strength Index),<ref>{{cite journal | vauthors = Klein J, Khartabil H, Boisson JC, Contreras-García J, Piquemal JP, Hénon E | title = New Way for Probing Bond Strength | journal = The Journal of Physical Chemistry A | volume = 124 | issue = 9 | pages = 1850–1860 | date = March 2020 | pmid = 32039597 | doi = 10.1021/acs.jpca.9b09845 | s2cid = 211070812 | bibcode = 2020JPCA..124.1850K | url = https://hal.archives-ouvertes.fr/hal-02377737/file/4_IGM_bond13012020_11h49%20%281%29.pdf }}</ref> relying on the IGM (Independent Gradient Model) methodology.<ref>{{cite journal | vauthors = Lefebvre C, Rubez G, Khartabil H, Boisson JC, Contreras-García J, Hénon E | title = Accurately extracting the signature of intermolecular interactions present in the NCI plot of the reduced density gradient versus electron density | journal = Physical Chemistry Chemical Physics | volume = 19 | issue = 27 | pages = 17928–17936 | date = July 2017 | pmid = 28664951 | doi = 10.1039/C7CP02110K | bibcode = 2017PCCP...1917928L | url = https://hal.univ-reims.fr/hal-02505160/file/2017_IGM_PROMOL%20%281%29.pdf }}</ref><ref>{{cite journal | vauthors = Lefebvre C, Khartabil H, Boisson JC, Contreras-García J, Piquemal JP, Hénon E | title = The Independent Gradient Model: A New Approach for Probing Strong and Weak Interactions in Molecules from Wave Function Calculations | journal = ChemPhysChem | volume = 19 | issue = 6 | pages = 724–735 | date = March 2018 | pmid = 29250908 | doi = 10.1002/cphc.201701325 | url = https://hal.univ-reims.fr/hal-03377532/file/37_version.pdf }}</ref><ref>{{cite journal | vauthors = Ponce-Vargas M, Lefebvre C, Boisson JC, Hénon E | title = Atomic Decomposition Scheme of Noncovalent Interactions Applied to Host-Guest Assemblies | journal = Journal of Chemical Information and Modeling | volume = 60 | issue = 1 | pages = 268–278 | date = January 2020 | pmid = 31877034 | doi = 10.1021/acs.jcim.9b01016 | s2cid = 209488458 }}</ref> | ||
| Line 162: | Line 167: | ||
{{DEFAULTSORT:Intermolecular Force}} | {{DEFAULTSORT:Intermolecular Force}} | ||
[[Category:Intermolecular forces]] | [[Category:Intermolecular forces| ]] | ||
[[Category:Chemical bonding]] | [[Category:Chemical bonding]] | ||
[[Category:Johannes Diderik van der Waals]] | [[Category:Johannes Diderik van der Waals]] | ||