Stilbene
Encyclopedia
-Stilbene, is a diarylethene
, i.e., a hydrocarbon
consisting of a trans ethene double bond substituted with a phenyl group on both carbon atoms of the double bond. The name stilbene is derived from the Greek
word stilbos, which means shining.
or cis-stilbene, and is sterically hindered and less stable because the steric interactions force the aromatic rings out-of-plane and prevent conjugation
. (Z)-Stilbene has a melting point of 5-6 °C, while (E)-stilbene melts around 125 °C, illustrating the two compounds are quite different in their physical properties.
Table 1. Vapor pressures
Diarylethene
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...
, i.e., a hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
consisting of a trans ethene double bond substituted with a phenyl group on both carbon atoms of the double bond. The name stilbene is derived from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
word stilbos, which means shining.
Isomers
Stilbene exists as two possible isomers. The first is trans-1,2-diphenylethylene, called (E)-stilbene or trans-stilbene. The second is cis-1,2-diphenylethylene, called (Z)-stilbene(Z)-Stilbene
-Stilbene is a diarylethene, that is, a hydrocarbon consisting of a cis ethene double bond substituted with a phenyl group on both carbon atoms of the double bond. The name stilbene was derived from the Greek word stilbos, which means shining....
or cis-stilbene, and is sterically hindered and less stable because the steric interactions force the aromatic rings out-of-plane and prevent conjugation
Conjugated system
In chemistry, a conjugated system is a system of connected p-orbitals with delocalized electrons in compounds with alternating single and multiple bonds, which in general may lower the overall energy of the molecule and increase stability. Lone pairs, radicals or carbenium ions may be part of the...
. (Z)-Stilbene has a melting point of 5-6 °C, while (E)-stilbene melts around 125 °C, illustrating the two compounds are quite different in their physical properties.
Table 1. Vapor pressures
| Isomer | Temperature, °C | Vapor pressure, kPa |
|---|---|---|
| cis-stilbene | 100 | 0.199 |
| cis-stilbene | 125 | 0.765 |
| cis-stilbene | 150 | 2.51 |
| trans-stilbene | 150 | 0.784 |
Uses
- Stilbene is used in manufacture of dyeDyeA dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
s and optical brightenerOptical brightenerOptical brighteners, optical brightening agents , fluorescent brightening agents or fluorescent whitening agents are dyes that absorb light in the ultraviolet and violet region of the electromagnetic spectrum, and re-emit light in the blue region...
s, and also as a phosphorPhosphorA phosphor, most generally, is a substance that exhibits the phenomenon of luminescence. Somewhat confusingly, this includes both phosphorescent materials, which show a slow decay in brightness , and fluorescent materials, where the emission decay takes place over tens of nanoseconds...
and a scintillatorScintillatorA scintillator is a special material, which exhibits scintillation—the property of luminescence when excited by ionizing radiation. Luminescent materials, when struck by an incoming particle, absorb its energy and scintillate, i.e., reemit the absorbed energy in the form of light...
.
- Stilbene is one of the gain mediums used in dye laserDye laserA dye laser is a laser which uses an organic dye as the lasing medium, usually as a liquid solution. Compared to gases and most solid state lasing media, a dye can usually be used for a much wider range of wavelengths. The wide bandwidth makes them particularly suitable for tunable lasers and...
s.
- Many stilbene derivates (stilbenoids) are present naturally in plants. An example is resveratrolResveratrolResveratrol is a stilbenoid, a type of natural phenol, and a phytoalexin produced naturally by several plants when under attack by pathogens such as bacteria or fungi....
and its cousin, pterostilbenePterostilbenePterostilbene is a stilbenoid chemically related to resveratrol and is found in blueberries and grapes. It belongs to the group of phytoalexins, agents produced by plants to fight infections. Based on animal studies it is thought to exhibit anti-cancer, anti-hypercholesterolemia,...
.
- Stilbene derivatives especially E(trans) isomer have estrogenic activity so used in making non-steroidal synthetic estrogens such as Diethyl stilbestrol, Fosfosterol, Dienesterol.
Chemistry
- Stilbene will typically have the chemistry of a conjugated alkene, i.e., a diaryletheneDiaryletheneIn 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...
.
- Trans- and cis-stilbene can interconvert under the influence of light.