Synthesis of polymers with isolated thiophene-arylidene-thiophene chromophores for enhanced and specific electron/hole transport

The synthesis of nine new polymers intended for future use in light emittin g diodes is described. The polymers consist of alternating units of thiophe ne-arylidene-thiophene chromophores and saturated silicon-containing spacer s. The arylidene moieties include benzene-1,4-, 2,5-dimethoxyhenzene-1,4-, naphthalene-1,4-, anthracene-9,10-, pyridine-2,5-, pyridine-2,6-, N-methylc arbazole-3,6-, 1,3,4-oxadiazole-2,5-, and 4,4'-dimethyl-2,2'-bithiazole-5,5 '-. The syntheses involved dibromination of the central arene followed by S uzuki or Kumada cross-coupling reactions with two thiophene units. Subseque nt dilithiation and reaction with dihalosilylalkanes provided the polymers. Their optical properties, including ultraviolet-visible absorption and emi ssion in solution, were comparable to those of the parent monomer units, an d they possessed the physical characteristics of macromolecules. (C) 2001 J ohn Wiley & Sons, Inc.