(E)-Stilbene, trans-Stilbene, trans-1,2-Diphenylethylene
|Molar mass||180.25 g·mol−1|
|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)|
|Flash point||>112 °C (234 °F)|
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
(E)-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.
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 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 (41–43 °F), while (E)-stilbene melts around 125 °C (257 °F), illustrating the two compounds are quite different in their physical properties.
Table 1. Vapor pressures
|Isomer||Temperature, °C||Vapor pressure, kPa|
- Stilbene is used in manufacture of dyes and optical brighteners, and also as a phosphor and a scintillator.
- Many stilbene derivates (stilbenoids) are present naturally in plants. An example is resveratrol and its cousin, pterostilbene.
- Stilbene derivatives especially E(trans) isomer have estrogenic activity so used in making non-steroidal synthetic estrogens such as Diethylstilbestrol, Fosfestrol, Dienestrol.
- Trans- and cis-stilbene can interconvert under the influence of light.