SYNTHESIS AND PROPERTIES OF POLY[1-(N-ALKYLTHIO)-1-PROPYNES]

1-(n-Alkylthio)-1-propynes (CH3C≡CSR; R = CH3, C2H5, n-C4H9, n-C6H13, n-C8H17, and n-C10H21) could be polymerized in high yield (50-80%) in toluene at 80 °C in the presence of MoCl5-Ph3SiH (1:2) catalyst. The corresponding W, Nb, and Ta catalysts were less effective. The product polymers possessed weight average molecular weights up to 1 × 105-2 × 105, higher than any other sulfur-containing polyacetylenes so far synthesized. Spectroscopic data supported that the polymer structure was -(CCH3=CSR)n-. Except for poly[1-(methylthio)-1-propyne], the present polymers totally dissolved in common solvents such as toluene and CHCl3. They were colorless, film forming, thermally fairly stable in air, electrically insulating, and moderately permeable to gases. © 1990, American Chemical Society. All rights reserved.