Preparation and optical properties of soluble π-conjugated poly(aryleneethynylene) type polymers

π-Conjugated poly(aryleneethynylene) type polymers [graphic omitted]CC–Ar–CC–Ar′[graphic omitted]-n(Ar and/or Ar′= pyridine-2,5-diyl or alkyl-substituted arylene) synthesized by a palladium-catalysed coupling reaction are soluble in organic solvents and processable to make good thin films by casting, have large refractive index increment (Δn/Δc= 0.29–0.38), and exhibit photoluminescence as well as fairly strong third harmonic generation, χ(3) value of about 10–10 esu.