Editing Dimerization (section)

== Noncovalent dimers ==
[[File:Carboxylic acid dimers.svg|thumb|class=skin-invert-image|Dimers of [[carboxylic acid]]s are often found in the vapour phase.]]
[[Anhydrous]] [[carboxylic acid]]s form dimers by hydrogen bonding of the acidic hydrogen and the carbonyl oxygen. For example, [[acetic acid]] forms a dimer in the gas phase, where the monomer units are held together by [[hydrogen bond]]s.<ref>{{Cite journal |last1=Karle |first1=J. |last2=Brockway |first2=L. O. |date=1944 |title=An Electron Diffraction Investigation of the Monomers and Dimers of Formic, Acetic and Trifluoroacetic Acids and the Dimer of Deuterium Acetate 1 |url=https://pubs.acs.org/doi/abs/10.1021/ja01232a022 |journal=Journal of the American Chemical Society |language=en |volume=66 |issue=4 |pages=574–584 |doi=10.1021/ja01232a022 |issn=0002-7863|url-access=subscription }}</ref> Many OH-containing molecules form dimers, e.g. the [[water dimer]].

Dimers that form based on weak [[Electrostatic Interaction|electrostatic interaction]] and/or [[van der Waals interactions]] have a short lifetime, but can be stabilized through special laboratory setups such as [[Matrix isolation|matrix-isolation]]. A prominent example is the [[carbon dioxide]] dimer,<ref>{{Cite journal |last=Fredin |first=Leif |last2=Nelander |first2=Bengt |last3=Ribbegård |first3=Göran |date=1974-12-01 |title=On the dimerization of carbon dioxide in nitrogen and argon matrices |url=https://linkinghub.elsevier.com/retrieve/pii/0022285274900770 |journal=Journal of Molecular Spectroscopy |volume=53 |issue=3 |pages=410–416 |doi=10.1016/0022-2852(74)90077-0 |issn=0022-2852|url-access=subscription }}</ref> which is likely to be relevant to Venus atmosphere. <ref>{{Cite journal |last=Dinu |first=Dennis F. |last2=Bartl |first2=Pit |last3=Quoika |first3=Patrick K. |last4=Podewitz |first4=Maren |last5=Liedl |first5=Klaus R. |last6=Grothe |first6=Hinrich |last7=Loerting |first7=Thomas |date=2022-05-19 |title=Increase of Radiative Forcing through Midinfrared Absorption by Stable CO2 Dimers? |url=https://pubs.acs.org/doi/10.1021/acs.jpca.2c00857 |journal=The Journal of Physical Chemistry A |volume=126 |issue=19 |pages=2966–2975 |doi=10.1021/acs.jpca.2c00857 |issn=1089-5639 |pmc=9125687 |pmid=35533210}}</ref> 

[[Excimers]] and [[exciplex]]es are [[Excited state|excited]] structures with a short lifetime. For example, [[noble gases]] do not form stable dimers, but they do form the [[excimers]] Ar<sub>2</sub>*, Kr<sub>2</sub>* and Xe<sub>2</sub>* under high pressure and electrical stimulation.<ref>{{Cite journal |last=Birks |first=J B |date=1975-08-01 |title=Excimers |url=https://iopscience.iop.org/article/10.1088/0034-4885/38/8/001 |journal=Reports on Progress in Physics |volume=38 |issue=8 |pages=903–974 |doi=10.1088/0034-4885/38/8/001 |s2cid=240065177 |issn=0034-4885|url-access=subscription }}</ref>