Divinylarenes

Haloarene derivatives used for coordination polycondensation are primarily represented by halostyrenes and haloarylacetylenes which undergo selfcoupling to poly(arylene vinylene)s [scheme (2)] and poly(aryleneacetylene)s [scheme (3)] respectively, and by dihaloarenes which, mainly in a combination with alkenes or divinylarenes and acetylenes or diacetylenes, undergo crosscoupling to poly(arylene vinylene)s [schemes (4) and (5)] and poly(arylene acetylene)s [schemes (6) and (7)] respectively [2] ... 

Also, divinylarenes such as 1,4-divinylbenzene can undergo metathesis polycondensation according to scheme (1) [10-12]. 

A silylene divinylarene copolymer (226) is also considered to take a single-handed helical conformation in solution." A a-7T-conjugated poly(m-phenylenedisilanylene) (227) has been prepared. The helical handedness of 227 can be biased by complexation with metal ions. Positive Cotton effects appeared in the presence of Li", while negative Cotton effects appeared in the presence of Na, IC, Cu, or Zn""."""... 

Another way to poly(arylene vinylene)s is the condensation metathesis polymerisation of divinylarenes. Thus poly(phenylene vinylene)s were synthesised with high stereo-... 

From the point of view of synthesis of aromatic compounds, a 6% electron cyclization of either a 1,3,5-hexatiiene or 1,2-divinylarene derivative followed hy oxidation would be an appropriate strategy (Scheme 16.1). The intermediate dihydroaromatic derivatives can be oxidized to the fuUy aromatic compounds by a variety of oxidizing and dehydrogenating agents. 

Weychardt, H.and Plenio, H. (2008) Acyclic diene metathesis polymerization of divinylarenes and divinylferiocenes with gmbbs-type olefin metathesis catalysts. Organometallics, 27,1479-1485. 

Heck Reaction Polymerizations. The Heck reaction is readily applicable to the synthesis of poly(arylenevinylene)s and poly(heteroarylvinylene)s. Poly(l,4-phenylenevinylene)s have been prepared with both AA/BB-monomer pairs and AB-monomers. The AA/BB-monomer pairs are typically dihalogenated arenes and ethylene (797) or divinylarenes (798). Bromostj ene (equation 61) is an example of an AB-monomer (799). The molecular weight of the polymer obtained by the polymerization of 4-bromostyrene (equation 61) was limited by its poor solubility (799). 

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