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- Diarylethene abstract "In chemistry, diarylethene is the general name of a class of compounds that have aromatic groups bonded to each end of a carbon–carbon double bond. The simplest example is stilbene, which has two geometric isomers, E and Z.Under the influence of light, these compounds can generally perform two kinds of reversible isomerizations:E to Z isomerizations, most common for stilbenes (and azobenzenes). This process goes through an excited state energy minimum where the aromatic rings lie at 90° to each other. This conformation drops to the ground state and generally relaxes to trans and cis forms in a 1:1 ratio, thus the quantum yield for E-Z isomerization is very rarely greater than 0.5.6π electrocyclizations of the Z form, leading to an additional bond between the two aryl functionalities and a disruption of the aromatic character of these groups. The quantum yield of this reaction is generally less than 0.1, and in most diarylethenes the close-ring form is thermally unstable, reverting to the cis-form in a matter of seconds or minutes under ambient conditions.Thermal isomerization is also possible. In E-Z isomerization, the thermal equilibrium lies well towards the trans-form because of its lower energy (~15 kJ mol−1 in stilbene). The activation energy for thermal E-Z isomerization is 150–190 kJ mol−1 for stilbene, meaning that temperatures above 200°C are required to isomerize stilbene at a reasonable rate, but most derivatives have lower energy barriers (e.g. 65 kJ mol−1 for 4-aminostilbene). The activation energy of the electrocyclization is 73 kJ mol−1 for stilbene.Both processes are often applied in molecular switches and for photochromism (reversible state changes from exposure to light).After the 6π electrocyclization of the Z form to the \"close-ring\" form, most unsubstituted diarylethenes are prone to oxidation, leading to a re-aromatization of the π-system. The most common example is E-stilbene, which upon irradiation undergoes an E to Z isomerization, which can be followed by a 6π electrocyclization. Reaction of the product of this reaction with molecular oxygen affords phenanthrene, and it has been suggested by some studies that dehydrogenation may even occur spontaneously. The dihydrophenanthrene intermediate has never been isolated, but it has been detected spectroscopically in pump-probe experiments by virtue of its long wavelength optical absorption band. Although both the E-Z isomerization and the 6π electrocyclization are reversible processes, this oxidation renders the entire sequence irreversible.".
- Diarylethene thumbnail Stilbene_isomerization2.png?width=300.
- Diarylethene wikiPageID "1117237".
- Diarylethene wikiPageLength "7377".
- Diarylethene wikiPageOutDegree "64".
- Diarylethene wikiPageRevisionID "675036791".
- Diarylethene wikiPageWikiLink (E)-Stilbene.
- Diarylethene wikiPageWikiLink 3D_optical_data_storage.
- Diarylethene wikiPageWikiLink Absorption_spectroscopy.
- Diarylethene wikiPageWikiLink Alkene.
- Diarylethene wikiPageWikiLink Arene_substitution_pattern.
- Diarylethene wikiPageWikiLink Aromaticity.
- Diarylethene wikiPageWikiLink Aryl.
- Diarylethene wikiPageWikiLink Azobenzene.
- Diarylethene wikiPageWikiLink Carbon.
- Diarylethene wikiPageWikiLink Category:Aromatic_compounds.
- Diarylethene wikiPageWikiLink Chemical_compound.
- Diarylethene wikiPageWikiLink Chemical_structure.
- Diarylethene wikiPageWikiLink Chemistry.
- Diarylethene wikiPageWikiLink Cis–trans_isomerism.
- Diarylethene wikiPageWikiLink Conjugated_system.
- Diarylethene wikiPageWikiLink Conrotatory_and_disrotatory.
- Diarylethene wikiPageWikiLink Double_bond.
- Diarylethene wikiPageWikiLink Electrocyclic_reaction.
- Diarylethene wikiPageWikiLink Enantiomer.
- Diarylethene wikiPageWikiLink Excited_state.
- Diarylethene wikiPageWikiLink Functional_group.
- Diarylethene wikiPageWikiLink Ground_state.
- Diarylethene wikiPageWikiLink Isomer.
- Diarylethene wikiPageWikiLink Isomerization.
- Diarylethene wikiPageWikiLink Methyl_group.
- Diarylethene wikiPageWikiLink Molecular_switch.
- Diarylethene wikiPageWikiLink Optical_disc.
- Diarylethene wikiPageWikiLink Oxygen.
- Diarylethene wikiPageWikiLink Phenanthrene.
- Diarylethene wikiPageWikiLink Photochromism.
- Diarylethene wikiPageWikiLink Quantum_yield.
- Diarylethene wikiPageWikiLink Racemic_mixture.
- Diarylethene wikiPageWikiLink Redox.
- Diarylethene wikiPageWikiLink Refractive_index.
- Diarylethene wikiPageWikiLink Relative_permittivity.
- Diarylethene wikiPageWikiLink Reversible_reaction.
- Diarylethene wikiPageWikiLink Solid.
- Diarylethene wikiPageWikiLink Solution.
- Diarylethene wikiPageWikiLink Stereocenter.
- Diarylethene wikiPageWikiLink Steric_effects.
- Diarylethene wikiPageWikiLink Stilbene.
- Diarylethene wikiPageWikiLink Thermal_equilibrium.
- Diarylethene wikiPageWikiLink Thiophene.
- Diarylethene wikiPageWikiLink Ultraviolet.
- Diarylethene wikiPageWikiLink Woodward–Hoffmann_rules.
- Diarylethene wikiPageWikiLink File:Dithienylethene.png.
- Diarylethene wikiPageWikiLink File:Stilbene_isomerization2.png.
- Diarylethene wikiPageWikiLinkText "Diarylethene".
- Diarylethene wikiPageWikiLinkText "diarylethene".
- Diarylethene wikiPageUsesTemplate Template:Reflist.
- Diarylethene subject Category:Aromatic_compounds.
- Diarylethene hypernym Name.
- Diarylethene comment "In chemistry, diarylethene is the general name of a class of compounds that have aromatic groups bonded to each end of a carbon–carbon double bond. The simplest example is stilbene, which has two geometric isomers, E and Z.Under the influence of light, these compounds can generally perform two kinds of reversible isomerizations:E to Z isomerizations, most common for stilbenes (and azobenzenes).".
- Diarylethene label "Diarylethene".
- Diarylethene sameAs Q4180469.
- Diarylethene sameAs ジアリールエテン.
- Diarylethene sameAs m.047hg1.
- Diarylethene sameAs Diaryletén.
- Diarylethene sameAs Q4180469.
- Diarylethene wasDerivedFrom Diarylethene?oldid=675036791.
- Diarylethene depiction Stilbene_isomerization2.png.
- Diarylethene isPrimaryTopicOf Diarylethene.