Synthesis of Highly Phenylated Poly(p-phenylenevinylenes) via a Chlorine Precursor Route

The synthesis of several highly phenylated poly(p-phenylenevinylene) (PPV) derivatives by a chlorine precursor route was investigated in order to understand its scope. Three 1,4-bis(chloromethyl)benzene monomers were prepared via a robust and versatile synthetic procedure involving the Diels−Alder reaction. In the presence of 1.1 equiv of potassium tert-butoxide, the monomers underwent 1,6-dehydrochlorination to form the respective xylylenes which underwent 1,6-polymerization to give the corresponding chlorine precursor polymers. The 1,6-polymerization mechanism of the highly phenylated monomers is discussed. Only one monomer gave a soluble precursor polymer while the other two gave insoluble precursor polymers. The soluble precursor polymer was deposited as thin films and then converted to the corresponding PPV derivative, which showed green photoluminesence and electroluminesence.