Dendritic Poly phenylene s and Giant Polyaromatic Hydrocarbons PAHs

3 Dendritic Poly(phenylene)s and Giant Polyaromatic Hydrocarbons (PAHs) 

More recently, Mullen et al. have worked out very efficient procedures to generate highly arylated, branched oligo(phenylene) and related oligo(arylene) derivatives following different synthetic approaches. 

A first milestone was the development of a novel intramolecular Diels-Alder cyclization of terphenyl monomers 35 and 38 containing both 4-phenylbutadienyl 

The branched oligo(arylene)s 37 and 40 can undergo a further oxidative cyclization with copper(II) chloride or triflate/aluminum trichloride leading to the formation of large, hitherto unknown polycyclic aromatic hydrocarbons PAHs 41 and 42. 

In a second novel approach, Mullen and co-workers further developed an inter-molecular repetitive Diels-Alder procedure for the generation of dendritic and hy-perbranched poly(phenylene)s. Hereby, they applied the concept of reacting A2B-type monomers, in this case monomers containing both cyclopentadienone (dien- 

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