- Source: 1,1-Diphenylethylene
1,1-Diphenylethylene is an aromatic hydrocarbon with chemical formula C14H12.
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. 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. Dibenzofulvene is an analogue of a 1,1-Diphenylethylene.
Synthesis
1,1-Diphenylethylene is technical prepared by alkylating benzene by styrene in presence of a zeolite beta and subsequent dehydrogenation.
styrene + benzene → 1,1-diphenylethane → 1,1-diphenylethylene + H2
See also
Dibenzofulvene
Stilbene
