(''E'')-Stilbene, commonly known as ''trans''-stilbene, is an
organic compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...
represented by the
condensed structural formula CHCH=CHCH. Classified as a
diarylethene Diarylethene is the general name of a class of chemical compounds that have aromatic functional 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 influe ...
, it features a central
ethylene
Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon–carbon bond, carbon–carbon doub ...
moiety
Moiety may refer to:
__NOTOC__ Anthropology
* Moiety (kinship), either of two groups into which a society is divided
** A division of society in the Iroquois societal structure in North America
** An Australian Aboriginal kinship group
** Native Ha ...
with one
phenyl
In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula , and is often represented by the symbol Ph (archaically φ) or Ø. The phenyl group is closely related to benzene and can be viewed as a benzene ...
group
substituent
In organic chemistry, a substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule.
The suffix ''-yl'' is used when naming organic compounds that contain a single bond r ...
on each end of the carbon–carbon
double bond
In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...
. It has an
(''E'') stereochemistry, meaning that the phenyl groups are located on opposite sides of the double bond, the opposite of its
geometric isomer
Geometry (; ) is a branch of mathematics concerned with properties of space such as the distance, shape, size, and relative position of figures. Geometry is, along with arithmetic, one of the oldest branches of mathematics. A mathematician w ...
,
''cis''-stilbene. ''Trans''-stilbene occurs as a white crystalline solid at room temperature and is highly soluble in organic solvents. It can be converted to ''cis''-stilbene
photochemically, and further reacted to produce
phenanthrene
Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) with formula C14H10, consisting of three fused benzene rings. It is a colorless, crystal-like solid, but can also appear yellow. Phenanthrene is used to make dyes, plastics, pesticides, expl ...
.
Stilbene was discovered in 1843 by the French chemist
Auguste Laurent
Auguste Laurent (14 November 1807 – 15 April 1853) was a French chemist who helped in the founding of organic chemistry with his discoveries of trichloroethylene, anthracene, phthalic acid, and carbolic acid.
He devised a systematic nomenc ...
. The name "stilbene" is derived from the
Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
word ''στίλβω'' (''stilbo''), which means "I shine", on account of the lustrous appearance of the compound.
Isomers

Stilbene exists as two possible
stereoisomer
In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in ...
s. One is ''trans''-1,2-diphenylethylene, called (''E'')-stilbene or ''
trans
Trans- is a Latin prefix meaning "across", "beyond", or "on the other side of".
Used alone, trans may refer to:
Sociology
* Trans, a sociological term which may refer to:
** Transgender, people who identify themselves with a gender that di ...
''-stilbene. The second is ''cis''-1,2-diphenylethylene, called
(''Z'')-stilbene or ''
cis''-stilbene, and is
sterically hindered and less stable because the steric interactions force the aromatic rings out-of-plane and prevent
conjugation
Conjugation or conjugate may refer to:
Linguistics
*Grammatical conjugation, the modification of a verb from its basic form
*Emotive conjugation or Russell's conjugation, the use of loaded language
Mathematics
*Complex conjugation, the change o ...
. ''Cis''-stilbene is a liquid at room temperature (melting point: ), while ''trans''-stilbene is a crystalline solid which does not melt until around , illustrating the two isomers have significantly different physical properties.
Preparation and reactions
Many syntheses have been developed. One popular route entails reduction of
benzoin using zinc amalgam.
:
CH–CH(OH)–C(=O)–CH -> ce\ce \text \ce] ''trans''-CH–CH=CH–CH
Both isomers of stilbene can be produced by decarboxylation of
alpha-phenylcinnamic acid, α-phenylcinnamic acid, ''trans''-stilbene being produced from the of the acid.
Richard F. Heck
Richard Frederick Heck (August 15, 1931 – October 9, 2015) was an American chemist noted for the discovery and development of the Heck reaction, which uses palladium to catalyze organic chemical reactions that couple aryl halides with alken ...
and Tsutomu Mizoroki independently reported the synthesis of ''trans''-stilbene by coupling of
iodobenzene
Iodobenzene is an aryl iodide and the simplest of the iodobenzenes, consisting of a benzene ring substituted with one iodine atom. Its chemical formula is . It is useful as a synthetic intermediate in organic chemistry. It is a volatile colorles ...
and
styrene
Styrene is an organic compound with the chemical formula C6H5CH=CH2. Its structure consists of a vinyl group as substituent on benzene. Styrene is a colorless, oily liquid, although aged samples can appear yellowish. The compound evaporates easi ...
using a palladium(II) catalyst, in what is now known as the
Mizoroki-Heck reaction. The Mizoroki approach produced the higher yield.
:

Stilbene undergoes reactions typical of alkenes. ''Trans''-stilbene undergoes epoxidation with
peroxymonophosphoric acid
Peroxymonophosphoric acid () is an oxyacid of phosphorus. It is a colorless viscous oil. Its salts are called peroxymonophosphates. Another peroxyphosphoric acid is peroxydiphosphoric acid, .
Preparation
Peroxyphosphoric acids were first synt ...
, HPO, producing a 74% yield of ''trans''-stilbene oxide in
dioxane
Dioxane may refer to the following chemical compounds:
* 1,2-dioxane
* 1,3-dioxane
* 1,4-dioxane
{{Authority control ...
. The
epoxide
In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ...
product formed is a
racemic mixture
In chemistry, a racemic mixture or racemate () is a mixture that has equal amounts (50:50) of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as r ...
of the two
enantiomers
In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities whi ...
of 1,2-diphenyl
oxirane. The
achiral
Chirality () is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek (''kheir''), "hand", a familiar chiral object.
An object or a system is ''chiral'' if it is distinguishable from ...
''meso'' compound (1''R'',2''S'')-1,2-diphenyloxirane arises from ''cis''-stilbene, though peroxide epoxidations of the ''cis''-isomer produce both ''cis''- and ''trans''-epoxide products. For example, using
''tert''-butyl hydroperoxide, oxidation of ''cis''-stilbene produces 0.8% ''cis''-stilbene oxide, 13.5% ''trans''-stilbene oxide, and 6.1%
benzaldehyde
Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is among the simplest aromatic aldehydes and one of the most industrially useful.
It is a colorless liquid with a characteristic almond-li ...
. Enantiopure stilbene oxide has been prepared by Nobel laureate
Karl Barry Sharpless
Karl Barry Sharpless (born April 28, 1941) is an American stereochemist. He is a two-time Nobel laureate in chemistry, known for his work on stereoselective reactions and click chemistry.
Sharpless was awarded half of the 2001 Nobel Prize i ...
.
:

Stilbene can be cleanly oxidised to benzaldehyde by
ozonolysis
In organic chemistry, ozonolysis is an organic reaction where the Saturated and unsaturated compounds, unsaturated bonds are Bond cleavage, cleaved with ozone (). Multiple carbon–carbon bond are replaced by carbonyl () groups, such as aldehydes ...
or
Lemieux–Johnson oxidation, and stronger oxidants such as acidified
potassium permanganate
Potassium permanganate is an inorganic compound with the chemical formula KMnO4. It is a purplish-black crystalline salt, which dissolves in water as K+ and ions to give an intensely pink to purple solution.
Potassium permanganate is widely us ...
will produce
benzoic acid
Benzoic acid () is a white (or colorless) solid organic compound with the formula , whose structure consists of a benzene ring () with a carboxyl () substituent. The benzoyl group is often abbreviated "Bz" (not to be confused with "Bn," which ...
.
Vicinal diol
A diol is a chemical compound containing two hydroxyl groups ( groups). An aliphatic diol may also be called a glycol. This pairing of functional groups is pervasive, and many subcategories have been identified. They are used as protecting gro ...
s can be produced via the
Upjohn dihydroxylation
The Upjohn dihydroxylation is an organic reaction which converts an alkene to a ''cis'' vicinal diol. It was developed by V. VanRheenen, R. C. Kelly and D. Y. Cha of the Upjohn Company in 1976. It is a catalytic system using ''N''-methylmorph ...
or
enantioselective
In chemistry, stereoselectivity is the property of a chemical reaction in which a single reactant forms an unequal mixture of stereoisomers during a non- stereospecific creation of a new stereocenter or during a non-stereospecific transformation o ...
ly using
Sharpless asymmetric dihydroxylation
Sharpless asymmetric dihydroxylation (also called the Sharpless bishydroxylation) is the chemical reaction of an alkene with osmium tetroxide in the presence of a chirality (chemistry), chiral quinine ligand to form a Vicinal (chemistry), vicinal ...
with
enantiomeric excess
In stereochemistry, enantiomeric excess (ee) is a measurement of purity used for chiral substances. It reflects the degree to which a sample contains one enantiomer in greater amounts than the other. A racemic mixture has an ee of 0%, while a sing ...
es as high as 100%.
Bromination of ''trans''-stilbene produces predominantly ''meso''-1,2-dibromo-1,2-diphenylethane (sometimes called
''meso''-stilbene dibromide), in line with a mechanism involving a cyclic
bromonium
A halonium ion is any onium ion containing a halogen atom carrying a positive charge. This cation has the general structure where X is any halogen and no restrictions on R, this structure can be cyclic or an open chain molecular structure. Halo ...
ion intermediate of a typical electrophilic
bromine addition reaction;
''cis''-stilbene yields a
racemic mixture
In chemistry, a racemic mixture or racemate () is a mixture that has equal amounts (50:50) of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as r ...
of the two
enantiomer
In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities whi ...
s of 1,2-dibromo-1,2-diphenylethane in a non-polar solvent such as
carbon tetrachloride
Carbon tetrachloride, also known by many other names (such as carbon tet for short and tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC), is a chemical compound with the chemical formula CCl4. It is a n ...
, but the extent of production of the
''meso'' compound increases with solvent polarity, with a yield of 90% in
nitromethane
Nitromethane, sometimes shortened to simply "nitro", is an organic compound with the chemical formula . It is the simplest organic nitro compound. It is a polar liquid commonly used as a solvent in a variety of industrial applications such as in ...
. The formation of small quantities of the two enantiomers of stilbene dibromide from the ''trans''-isomer suggests that the bromonium ion intermediate exists in
chemical equilibrium
In a chemical reaction, chemical equilibrium is the state in which both the Reagent, reactants and Product (chemistry), products are present in concentrations which have no further tendency to change with time, so that there is no observable chan ...
with a carbocation intermediate PhCHBr–C(H)Ph with a vacant
p orbital
In quantum mechanics, an atomic orbital () is a function describing the location and wave-like behavior of an electron in an atom. This function describes an electron's charge distribution around the atom's nucleus, and can be used to calc ...
vulnerable to nucleophilic attack from either face.
The addition of bromide or tribromide salts restores much of the stereospecificity even in solvents with a
dielectric constant
The relative permittivity (in older texts, dielectric constant) is the permittivity of a material expressed as a ratio with the electric permittivity of a vacuum. A dielectric is an insulating material, and the dielectric constant of an insul ...
above 35.
Upon UV irradiation it converts to ''cis''-stilbene, a classic example of a
photochemical reaction Organic photochemistry encompasses organic reactions that are induced by the action of light. The absorption of ultraviolet light by organic molecules often leads to reactions. In the earliest days, sunlight was employed, while in more modern times ...
involving
''trans''-''cis'' isomerization, and can undergo further reaction to form
phenanthrene
Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) with formula C14H10, consisting of three fused benzene rings. It is a colorless, crystal-like solid, but can also appear yellow. Phenanthrene is used to make dyes, plastics, pesticides, expl ...
.
:
Derivatives and uses
Synthetic
(''E'')-Stilbene itself is of little value, but it is a precursor to other derivatives used as
dye
Juan de Guillebon, better known by his stage name DyE, is a French musician. He is known for the music video of the single "Fantasy
Fantasy is a genre of speculative fiction that involves supernatural or Magic (supernatural), magical ele ...
s,
optical brightener
Optical brighteners, optical brightening agents (OBAs), fluorescent brightening agents (FBAs), or fluorescent whitening agents (FWAs), are chemical compounds that absorb light in the ultraviolet and violet region (usually 340-370 nm) of the ...
s,
phosphor
A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or ...
s, and
scintillator
A scintillator ( ) is a material that 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. re-emit the ab ...
s.
Stilbene is one of the
gain medium
The active laser medium (also called a gain medium or lasing medium) is the source of optical gain within a laser. The gain results from the stimulated emission of photons through electronic or molecular transitions to a lower energy state from ...
s used in
dye laser
A dye laser is a laser that 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, often spanning 50 to 100 n ...
s.
Disodium 4,4'-dinitrostilbene-2,2'-disulfonate is prepared by the
sulfonation
In organic chemistry, aromatic sulfonation is a reaction in which a hydrogen atom on an arene is replaced by a sulfonic acid () group. Together with nitration and chlorination, aromatic sulfonation is a widely used electrophilic aromatic substi ...
of
4-nitrotoluene to form 4-nitrotoluene-2-sulfonic acid, which can then be oxidatively coupled using
sodium hypochlorite
Sodium hypochlorite is an alkaline inorganic chemical compound with the formula (also written as NaClO). It is commonly known in a dilute aqueous solution as bleach or chlorine bleach. It is the sodium salt of hypochlorous acid, consisting of ...
to form the (''E'')-stilbene
derivative
In mathematics, the derivative is a fundamental tool that quantifies the sensitivity to change of a function's output with respect to its input. The derivative of a function of a single variable at a chosen input value, when it exists, is t ...
in a process originally developed by
Arthur George Green and André Wahl in the late nineteenth century. Improvements to the process with higher yields have been developed, using air oxidation in liquid ammonia. The product is useful as its reaction with
aniline
Aniline (From , meaning ' indigo shrub', and ''-ine'' indicating a derived substance) is an organic compound with the formula . Consisting of a phenyl group () attached to an amino group (), aniline is the simplest aromatic amine. It is an in ...
derivatives results in the formation of
azo dye
Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl and substituted aryl groups. They are a commercially important family of azo compounds, i.e. compounds containing the C−N=N−C l ...
s. Commercially important dyes derived from this compound include Direct Red 76, Direct Brown 78, and Direct Orange 40.
Natural stilbenes
The
stilbenoid
Stilbenoids are hydroxylated derivatives of stilbene. They have a C6–C2–C6 structure. In biochemical terms, they belong to the family of phenylpropanoids and share most of their biosynthesis pathway with Chalconoid, chalcones. Most stilbenoids ...
s are naturally occurring stilbene derivatives. Examples include
resveratrol
Resveratrol (3,5,4′-trihydroxy-''trans''-stilbene) is a stilbenoid, a type of natural phenol or polyphenol and a phytoalexin produced by several plants in response to injury or when the plant is under attack by pathogens, such as bacterium, ba ...
and its cousin,
pterostilbene
Pterostilbene () (trans-3,5-dimethoxy-4-hydroxystilbene) is a stilbenoid chemically related to resveratrol. In plants, it serves a defensive phytoalexin role.
Natural occurrence
Pterostilbene is found in almonds, various ''Vaccinium'' berries ( ...
. The
stilbestrol
Stilbestrol, or stilboestrol, also known as 4,4'-dihydroxystilbene or 4,4'-stilbenediol, is a stilbenoid nonsteroidal estrogen and the parent compound of a group of more potency (pharmacology), potent nonsteroidal estrogen chemical derivative, de ...
s, which are structurally but not synthetically related to (''E'')-stilbene, exhibit
estrogen
Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...
ic activity. Members of this group include
diethylstilbestrol
Diethylstilbestrol (DES), also known as stilbestrol or stilboestrol, is a nonsteroidal estrogen medication, which is presently rarely used. In the past, it was widely used for a variety of indications, including pregnancy support for those with ...
,
fosfestrol
Fosfestrol, sold under the brand name Honvan and also known as diethylstilbestrol diphosphate (DESDP), is an estrogen medication which is used in the treatment of prostate cancer in men. It is given by slow intravenous infusion once per day to o ...
, and
dienestrol
Dienestrol (, ) (brand names Dienoestrol, Denestrolin, Dienol and many others), also known as dienoestrol (), is a synthetic nonsteroidal estrogen medication of the stilbestrol group which is or was used to treat menopausal symptoms in the Unit ...
. Some such derivative are produced by
condensation
Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor ...
of coenzyme A derivatives of
cinnamic acid
Cinnamic acid is an organic compound with the formula phenyl, C6H5-CH=CH-Carboxylic acid, COOH. It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxy ...
or
4-hydroxycinnamic acid
''p''-Coumaric acid is an organic compound with the formula HOC6H4CH=CHCO2H. It is one of the three isomers of coumaric acid. It is a white solid that is only slightly soluble in water but very soluble in ethanol and diethyl ether.
Natural occur ...
and the malonic acid.
Appendix
Table 1. Vapor pressures
References
External links
(E)-Stilbene on ChemExper
{{DEFAULTSORT:Stilbene, (E)-
Luminescence
Fluorescent dyes
Phosphors and scintillators
Laser gain media
Stilbenoids
Phenyl compounds