STILBENE

Stilbene is a conjugated aromatic compound valued for its strong photochemical response and versatile molecular structure.
Stilbene is widely used in the development of fluorescent brighteners, optical materials, dyes, and photoresponsive systems.
Stilbene's ability to undergo light-induced structural changes also makes stilbene important in molecular switching, spectroscopy, and advanced materials research.

CAS Number: 103-30-0
EC Number: 203-098-5
CBNumber: CB8211190
Molecular Formula: C14H12
Molecular Weight: 180.25 g/mol

Synonyms: STILBENE, 1,2-Diphenylethylene, 588-59-0, Benzene, 1,1'-(1,2-ethenediyl)bis-, Bibenzal, Bibenzylidene, Bibenzylidine, DTXSID6060424, W1WNW14Z2I, CHEBI:26775, RefChem:1099074, DTXCID8042478, 209-621-3, 1,1'-(1,2-Ethenediyl)bisbenzene, 1,1'-(1,2-Ethenediyl)dibenzene, alpha,beta-Diphenylethylene, (2-phenylethenyl)benzene, 1,2-Diphenylethene, Stilben, .alpha.,.beta.-Diphenylethylene, phenylstyrene, 1,1'-(ethene-1,2-diyl)dibenzene, 1,2-diphenyl-ethylene, 1,2 Diphenyl Ethylene, SCHEMBL443, SCHEMBL48799, SCHEMBL152100, SCHEMBL191092, SCHEMBL339222, SCHEMBL339509, SCHEMBL496414, SCHEMBL619305, orb1297183, SCHEMBL2025150, SCHEMBL3656609, SCHEMBL4482993, SCHEMBL5664436, SCHEMBL10492226, AKOS025243560, DB-054687, D81842, F358024, Q26990366, 1,1′-[(E)-1,2-Ethenediyl]dibenzene, 1,1′-Ethene-1,2-diyldibenzene, 588-59-0, a,b-Diphenylethylene, benzene, 1,1′-(1,2-ethenediyl)bis-, stilbene, (2-phenylethenyl)benzene, 1,1′-(1,2-ethenediyl)bis[benzene], 1,1′-(1,2-Ethenediyl)bisbenzene, 1,1′-(ethene-1,2-diyl)dibenzene, 1,2-diphenylethylene, 1,2-Diphenylethylene (trans), (E)-Stilbene, 16341-52-9, 1904445, cis-Stilbene, MFCD00004788, Trans-1,2-Diphenylethene (1), Tyrosinase, α,β-DIPHENYLETHYLENE

Stilbene is an aromatic organic compound with the molecular formula C14H12, consisting of two benzene rings connected through an ethene bridge.
Stilbene occurs mainly in two geometric forms, trans-stilbene and cis-stilbene, with the trans form generally being the more stable configuration.

Stilbene is well known for its photochemical and photophysical properties, especially its ability to undergo light-induced cis-trans isomerization.
These characteristics make stilbene an important model compound in studies of molecular motion, excited-state chemistry, fluorescence, and photoresponsive behavior.

Stilbene derivatives are widely used in the manufacture of optical brightening agents for textiles, paper, detergents, and plastics because many substituted stilbenes can absorb ultraviolet radiation and emit visible blue light.
They are also used as intermediates in the synthesis of dyes, fluorescent compounds, specialty chemicals, and functional organic molecules.

In materials science, stilbene-based structures are investigated for applications in organic electronics, sensors, nonlinear optical materials, molecular switches, and light-responsive polymers.
The stilbene framework also appears in numerous naturally occurring and synthetic compounds, making it relevant in pharmaceutical, biochemical, and fine chemical research.

Common name for trans-1,2-diphenylethylene, aka, stilbene, or more specifically, (E)-stilbene, is the alkene, ethene with two phenyl groups on either carbon of the parent chain.
The name was derived from the Greek word stilbos, which means shining.

Stilbene should also be noted, there is also a (Z)-stilbene which is sterically hindered and less stable because of it.
Also notice that (Z)-stilbene has a melting point of 5°C to 6°C, while the melting point of (E)-stilbene is in the 125°C area, this illustrates the significant differences between the two.
Because (E)-stilbene is so much more common than (Z)-stilbene, this page will focus only on (E)-stilbene.

Stilbenes are defined as a group of phenylpropanoids characterized by a 1,2-diphenylethylene backbone, exhibiting various biological properties, including cardioprotective and antibacterial activities.
They are biosynthesized through the phenylpropanoid pathway and play defensive roles in plants, particularly in response to phytopathologic infections.

(E)-Stilbene, commonly known as trans-stilbene, is an organic compound represented by the condensed structural formula C6H5CH=CHC6H5.
Classified as a diarylethene, Stilbene features a central ethylene moiety with one phenyl group substituent on each end of the carbon–carbon double bond.

Stilbene has an (E) stereochemistry, meaning that the phenyl groups are located on opposite sides of the double bond, the opposite of its geometric isomer, cis-stilbene.
Trans-stilbene occurs as a white crystalline solid at room temperature and is highly soluble in organic solvents.
Stilbene can be converted to cis-stilbene photochemically, and further reacted to produce phenanthrene.

Stilbene was discovered in 1843 by the French chemist Auguste Laurent.
The name "stilbene" is derived from the Greek word στίλβω (stilbo), which means "I shine", on account of the lustrous appearance of the compound.

Derivatives and Uses of Stilbene:

Synthetic:
(E)-Stilbene itself is of little value, but Stilbene is a precursor to other derivatives used as dyes, optical brighteners, phosphors, and scintillators.
Stilbene is one of the gain mediums used in dye lasers.

Disodium 4,4'-dinitrostilbene-2,2'-disulfonate is prepared by the sulfonation of 4-nitrotoluene to form 4-nitrotoluene-2-sulfonic acid, which can then be oxidatively coupled using sodium hypochlorite to form the (E)-stilbene derivative[27] 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.

Stilbene is useful as its reaction with aniline derivatives results in the formation of azo dyes.
Commercially important dyes derived from this compound include Direct Red 76, Direct Brown 78, and Direct Orange 40.

Natural stilbenes:
The stilbenoids are naturally occurring stilbene derivatives.
Examples include resveratrol and its cousin, pterostilbene.

The stilbestrols, which are structurally but not synthetically related to (E)-stilbene, exhibit estrogenic activity.
Members of this group include diethylstilbestrol, fosfestrol, and dienestrol.
Some such derivative are produced by condensation of coenzyme A derivatives of cinnamic acid or 4-hydroxycinnamic acid and the malonic acid.

Uses of Stilbene:
Stilbene is used in manufacture of dyes and optical brighteners, and also as a phosphor and a scintillator.
Stilbene is one of the gain mediums used in dye lasers.

Many stilbene derivates (stilbenoids) are present naturally in plants.
An example is resveratrol and its cousin, pterostilbene.

Stilbene is widely used as a structural intermediate in the production of optical brighteners, fluorescent dyes, specialty chemicals, and functional organic compounds.
Stilbene derivatives are especially important in textile, paper, detergent, and plastics applications, where they can improve visual brightness by absorbing ultraviolet light and emitting blue fluorescence.

Stilbene is also used extensively in photochemistry and spectroscopy as a model system for studying cis-trans photoisomerization, fluorescence, and excited-state behavior.
In materials science, stilbene-based molecules are investigated for organic electronics, nonlinear optical materials, molecular switches, sensors, and light-responsive polymers.

Stilbene also serves as a useful building block in pharmaceutical and fine chemical synthesis.
Stilbene's conjugated aromatic structure makes it valuable in research involving molecular design, energy transfer, and photoresponsive functional materials.

Stilbene is commonly employed in transition metal catalyzed asymmetric epoxidation and dihydroxylation.
Stilbene is used to make dyes and optical brighteners.

Isomers of Stilbene:
Stilbene exists as two possible stereoisomers.
One is trans-1,2-diphenylethylene, called (E)-stilbene or trans-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.
Cis-stilbene is a liquid at room temperature (melting point: 5–6 °C (41–43 °F)), while trans-stilbene is a crystalline solid which does not melt until around 125 °C (257 °F), 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.

C6H5–CH(OH)–C(=O)–C6H5 →HCl, CH3CH2OHZn(Hg)

Both isomers of stilbene can be produced by decarboxylation of α-phenylcinnamic acid, trans-stilbene being produced from the (Z)-isomer of the acid.

Richard F. Heck and Tsutomu Mizoroki independently reported the synthesis of trans-stilbene by coupling of iodobenzene and styrene 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, H3PO5, producing a 74% yield of trans-stilbene oxide in dioxane.

The epoxide product formed is a racemic mixture of the two enantiomers of 1,2-diphenyloxirane.
The achiral meso compound (1R,2S)-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.
Enantiopure stilbene oxide has been prepared by Nobel laureate Karl Barry Sharpless.

Stilbene can be cleanly oxidised to benzaldehyde by ozonolysis or Lemieux–Johnson oxidation, and stronger oxidants such as acidified potassium permanganate will produce benzoic acid.
Vicinal diols can be produced via the Upjohn dihydroxylation or enantioselectively using Sharpless asymmetric dihydroxylation with enantiomeric excesses 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 ion intermediate of a typical electrophilic bromine addition reaction; cis-stilbene yields a racemic mixture of the two enantiomers of 1,2-dibromo-1,2-diphenylethane in a non-polar solvent such as carbon tetrachloride, but the extent of production of the meso compound increases with solvent polarity, with a yield of 90% in nitromethane.
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 with a carbocation intermediate PhCHBr–C+(H)Ph with a vacant p orbital 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 above 35.

Upon UV irradiation it converts to cis-stilbene, a classic example of a photochemical reaction involving trans-cis isomerization, and can undergo further reaction to form phenanthrene.

Reactions of Stilbene:

Halogenation of Stilbene:
Simple hydrocarbons are relatively unreactive.
In order to form more complex molecules, Stilbene is generally necessary to introduce more reactive functional groups.
Alkenes (olefins) containing the carbon-carbon double bond may be halogenated to form alkyl halides, which are more capable of undergoing further chemical reactions.

An example of halogenation is the bromination of (E)-stilbene.
Bromine is somewhat of a special case due in no small part, to its relatively enormous size compared to carbon.
Since elemental bromine (Br2) is volatile and highly corrosive, pyridinium tribromide is commonly used to generate Br2 in situ.

Green halogenation:
To green this reaction, the pyridinium tribromide in situ generation of Br2 is replaced with hydrobromic acid, which is oxidized by hydrogen peroxide(H2O2).

2HBr + H2O2 → Br2 + 2H2O

In either case the halogenation of stilbene is as follows; as seen in the first reaction, the Br-Br bond attracts the attention of the π-bonding electrons (π-bonds being e- dense and Br being very electronegative), this leads to a weakening and eventual break (heat, plays a crucial role in driving the break forward) of the π-bond.
Once the π-bond has been broken, Stilbene's electrons are transferred to Br2, causing the Br-Br bond to be severed when the bonding electrons are transferred to the other bromine.
At this stage there is the positively charged intermediate and the loose bromine ion (Br-), coming from the opposite direction as the Br2, the Br- loosens one of the C-Br Bonds, leaving the final brominated product.

Stilbene doesn't matter which stilbene is used for this reaction, (E)-stilbene and (Z)-stilbene will both produce 1,2-dibromo-1,2-diphenylethane.
However, bromination of the (Z) isomer results in a racemic mixture of dl stilbene dibromide, while the bromination of an (E) isomer results in a majority meso-stilbene dibromide along with minor amounts of the dl enantiomers.
The minor dl product in the bromination of (E)-stilbene is a result of resonance in the bromonium bridge intermediate, where a positive charge is located on one of the two bridge carbons, thus allowing for a syn-addition of a bromine anion.

Stability and Reactivity of Stilbene:

Chemical Stability:
Stable under normal recommended storage and handling conditions.

Reactivity:
No dangerous reactions are expected during normal use.

Conditions to Avoid:
Excessive heat, open flames, sparks, and prolonged exposure to incompatible materials.

Incompatible Materials:
Strong oxidizing agents.

Hazardous Decomposition Products:
Thermal decomposition or combustion may produce carbon monoxide, carbon dioxide, and irritating organic fumes.

Handling and Storage of Stilbene:

Safe Handling:
Avoid breathing dust and prevent contact with skin and eyes.
Use adequate ventilation and appropriate personal protective equipment.

Storage Conditions:
Keep the container tightly closed in a cool, dry, and well-ventilated area away from heat and incompatible substances.

First Aid Measures of Stilbene:

Inhalation:
Move the affected person to fresh air and seek medical attention if symptoms occur.

Skin Contact:
Remove contaminated clothing and wash the affected area thoroughly with soap and water.

Eye Contact:
Rinse cautiously with plenty of water for several minutes and obtain medical attention if irritation persists.

Ingestion:
Rinse the mouth with water and seek medical advice if discomfort occurs.

Firefighting Measures of Stilbene:

Suitable Extinguishing Media:
Use water spray, carbon dioxide, dry chemical powder, or suitable foam.

Specific Hazards:
Combustion may generate carbon oxides and irritating fumes.

Protective Equipment:
Firefighters should wear suitable protective clothing and self-contained breathing apparatus when necessary.

Accidental Release Measures of Stilbene:

Personal Precautions:
Ensure adequate ventilation, avoid dust formation, and wear suitable protective equipment.

Environmental Precautions:
Prevent uncontrolled release into drains, waterways, or soil.

Cleanup Methods:
Carefully sweep or collect spilled material without generating dust and place it in a suitable closed container for disposal.

Exposure Controls/Personal Protection of Stilbene:

Engineering Controls:
Provide adequate general ventilation or local exhaust ventilation.

Eye Protection:
Wear appropriate safety glasses or chemical goggles.

Hand Protection:
Wear suitable chemical-resistant gloves.

Skin Protection:
Wear appropriate protective clothing.

Respiratory Protection:
Use suitable particulate respiratory protection if ventilation is inadequate or airborne dust concentrations become elevated.

Identifiers of Stilbene:
CAS Number: 103-30-0
Beilstein Reference: 1616740
ChEBI: CHEBI:36007
ChEMBL: ChEMBL113028
ChemSpider: 553649
ECHA InfoCard: 100.002.817
EC Number: 203-098-5
Gmelin Reference: 4381
PubChem CID: 638088
UNII: 3FA7NW80A0
UN number: 3077
CompTox Dashboard (EPA): DTXSID4026050
InChI: InChI=1S/C14H12/c1-3-7-13(8-4-1)11-12-14-9-5-2-6-10-14/h1-12H/b12-11+
Key: PJANXHGTPQOBST-VAWYXSNFSA-N
InChI=1/C14H12/c1-3-7-13(8-4-1)11-12-14-9-5-2-6-10-14/h1-12H/b12-11+
Key: PJANXHGTPQOBST-VAWYXSNFBV
SMILES: c2(\C=C\c1ccccc1)ccccc2, c1ccc(cc1)/C=C/c2ccccc2

CAS No: 645-49-8
Chemical Name: CIS-STILBENE
CBNumber: CB8211190
Molecular Formula: C14H12
Molecular Weight: 180.25
MDL Number: MFCD00004788
MOL File: 645-49-8.mol

Product Number: S0090
Purity / Analysis Method : >98.0%(GC)
Molecular Formula / Molecular Weight: C14H12 = 180.25 
Physical State (20 deg.C): Solid
Storage Temperature : Room Temperature (Recommended in a cool and dark place, <15°C)
CAS RN: 103-30-0
Reaxys Registry Number: 1616740
PubChem Substance ID: 87575706
SDBS (AIST Spectral DB): 1844
Merck Index (14): 8817
MDL Number: MFCD00064300

Linear Formula:C6H5CH=CHC6H5
CAS Number:103-30-0
Molecular Weight:180.25
UNSPSC Code:12352103
NACRES:NA.23
PubChem Substance ID:24848441
EC Number:203-098-5
Beilstein/REAXYS Number:1616740
MDL number:MFCD00064300

Properties of Stilbene:
Chemical formula: C14H12
Molar mass: 180.250 g·mol−1
Appearance: Solid
Density: 0.9707 g/cm3
Melting point: 122 to 125 °C (252 to 257 °F; 395 to 398 K)
Boiling point: 305 to 307 °C (581 to 585 °F; 578 to 580 K)
Solubility in water: Practically insoluble

Quality Segment: 100
assay: 96%
form: solid
bp.: 305-307 °C/744 mmHg (lit.)
mp: 123-125 °C (lit.)
density: 0.97 g/mL at 25 °C (lit.)
SMILES string: c1ccc(cc1)\C=C\c2ccccc2
InChI: 1S/C14H12/c1-3-7-13(8-4-1)11-12-14-9-5-2-6-10-14/h1-12H/b12-11+
InChI key: PJANXHGTPQOBST-VAWYXSNFSA-N

Melting point: -5°C
Boiling point: 82-84 °C0.4 mm Hg(lit.)
Density: 1.011 g/mL at 25 °C(lit.)
refractive index: n20/D 1.622(lit.)
Flash point: >230 °F
storage temp.: 2-8°C
form: clear liquid
color: Colorless to Yellow to Green
Water Solubility: Immiscible with water. Miscible with ethanol.
Merck: 14,8817
BRN: 1616739
Stability: Stable. Combustible. Incompatible with strong oxidizing agents.
InChI: 1S/C14H12/c1-3-7-13(8-4-1)11-12-14-9-5-2-6-10-14/h1-12H/b12-11-
InChIKey: PJANXHGTPQOBST-QXMHVHEDSA-N
SMILES: c1ccc(cc1)\C=C/c2ccccc2
LogP: 4.830 (est)
CAS DataBase Reference: 645-49-8(CAS DataBase Reference)
EWG's Food Scores: 1
FDA UNII: TTG5048Y3K
EPA Substance Registry System: cis-Stilbene (645-49-8)
UNSPSC Code: 12352100
NACRES: NA.22

Molecular Weight: 180.24 g/mol
XLogP3: 4.8
Hydrogen Bond Donor Count: 0
Hydrogen Bond Acceptor Count: 0
Rotatable Bond Count: 2
Exact Mass: 180.093900383 Da
Monoisotopic Mass: 180.093900383 Da
Topological Polar Surface Area: 0 Ų
Heavy Atom Count: 14
Computed by PubChem
Complexity: 148
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 0
Defined Bond Stereocenter Count: 0
Undefined Bond Stereocenter Count: 1
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes

Specifications of Stilbene:
Appearance: White to Almost white powder to crystaline
Purity(GC): min. 98.0 %
Melting point: 123.0 to 126.0 °C
Solubility in Toluene: almost transparency

Names of Stilbene:

IUPAC name
(E)-Stilbene:

Preferred IUPAC name:
1,1′-[(E)-Ethene-1,2-diyl]dibenzene

Other names:
Bibenzylidene
trans-α,β-Diphenylethylene
(E)-1,2-Diphenylethylene
((1E)-2-Phenylvinyl)benzene
trans-Stilbene
[(E)-2-Phenylethenyl]benzene