1,1-Diphenylethylene
Chemical compound
From Wikipedia, the free encyclopedia
1,1-Diphenylethylene is an organic compound with chemical formula (C6H5)2C=CH2. It is a colorless to light orange to yellow clear liquid.[3]
| |
| Names | |
|---|---|
| Preferred IUPAC name
1,1â²-(Ethene-1,1-diyl)dibenzene | |
| Other names
Ethene-1,1-diyldibenzene | |
| Identifiers | |
3D model (JSmol) |
|
| ChemSpider | |
| ECHA InfoCard | 100.007.712 |
PubChem CID |
|
| UNII | |
CompTox Dashboard (EPA) |
|
| |
| |
| Properties | |
| C14H12 | |
| Molar mass | 180.250 g·molâ1 |
| Melting point | 8 °C[1] |
| Boiling point | 277 °C[2] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Properties
1,1-Diphenylethylene mediates the radical polymerization of methyl acrylate or styrene. Mediation by 1,1-diphenylethylene generates low molecular weight polymer by a termination reaction.[4] Additionally, because 1,1-diphenylethylene has a lower pKa than styrene, it is an effective mediator in the anionic living polymerization of styrene-block-methyl methacrylate copolymers. Polystyrene homopolymers can be "capped" with 1,1-Diphenylethylene before adding methyl methacrylate, effectively adjusting the pKa of the active chain end so that 1,4-addition to methyl methacrylate is favored over 1,2-addition.[5] Dibenzofulvene is an analogue of a 1,1-Diphenylethylene.[6]
Synthesis
1,1-Diphenylethylene is prepared commercially by alkylating benzene with styrene to give 1,1-diphenylethane. This conversion requires a zeolite catalyst. In a subsequent step, this ethane derivative undergoes dehydrogenation:[7]
- C6H5CH=CH2 + C6H6 â (C6H5)2CHCH3
- (C6H5)2CHCH3 â (C6H5)2C=CH2 + H2
A laboratory route to 1,1-diphenylethylene entails dehydration of 1,1-diphenylethanol.[8]