New polyacetylenes with aromatic Schiff's base pendant groups by polymerization of benzylidene-ring-substituted N-benzylidene-4-ethynylanilines with Rh-based catalysts

N-Benzylidene-4-ethynylanilines, R-C6H4-CH=N-C6H4-C=CH substituted in 4' po sition by R = H, t-Bu, F, Pr, CN, NO2 and Me2N, were polymerized in tetrahy drofuran using [Rh(cod)X](2) (cod = 1,5-cyclooctadiene; X = Cl, OCH3) as a catalyst to result in polyacetylene type polymers. Monomers with R = H, t-B u and F gave tetrahydrofuran-soluble polymers of molecular weights (M) over bar(w) from 15 000 to 100 000; monomers with Br, CN, NO2 and Me2N as subst ituents gave polymers insoluble in tetrahydrofuran and other common organic solvents. The polymer structure, consisting of conjugated polyene main cha in and 4-(N-benzylideneamino)phenyl pendant groups, was confirmed by IR, UV -vis and NMR spectroscopy.