SYNTHESIS OF POLYPHENYLENE DERIVATIVES BY THERMOLYSIS OF ENEDIYNES AND DIALKYNYLAROMATIC MONOMERS

Described are the syntheses of substituted enediynes and dialkynylarom atics using Pd- or Pd/Cu-catalyzed cross coupling procedures. The prod ucts were then thermalized to afford the corresponding poly(p-phenylen e)s, poly(1,4-naphthalene)s, poly(benzo[c]thiophene)s, and poly(dibenz othiophene)s. Fifteen examples are provided that show the scope of the polymerization process based upon substituent patterns and cyclizatio n moieties. The superb thermal resiliency of the newly derived polymer s is demonstrated using thermogravimetric analysis. The polymer struct ure was generally confirmed using IR data correlations to small molecu les that resembled the polymers' repeat unit structure. Radical trappi ng of dimeric intermediates, that were analyzed by GCMS, further subst antiated the proposed mechanistic route. The step-growth polymerizatio n pattern was determined by monitoring the degree of monomer consumpti on versus the polymer molecular weight. (C) 1997 Elsevier Science Ltd.