Poly(1-chloro-oct-1-yne): a new, high-molecular-weight polyacetylene synthesized with molybdenum catalysts

Abstract

Chloro-oct-I-yne polymerizes in the_ presence of Mo catalysts [e.g., MoC15, MoCls-Bun4Sn, MO(CO)~-CCI~-~V] to give a new, high-molecular-weight (M, up to 1 x 106), white, soluble, air-stable, electrically insulating polypolyacetylene, which is the first example of a polymer from a chlorine-containing aliphatic disubstituted acetylene.

Living polymerization of substituted acetylenes

“…In addition, one has to keep in mind that unwanted side reactions might occur because of, for example, the Lewis acidity of the components. Nonetheless, group 6 transition metal (Mo and W) halide‐based initiators produced high‐molecular‐weight polymers in excellent yields, especially from monosubstituted acetylenes with sterically demanding substituents such as t ‐butylacetylene61 or [ o ‐(trimethylsilyl)phenyl]acetylene ( o ‐TMSPA)62 but also from disubstituted acetylenes with less steric hindrance, such as 1‐chloro‐1‐octyne63, 64 or 2‐octyne 65. In contrast, group 5 transition metal (Nb and Ta) halide‐based initiators tend to give selectively cyclotrimers from most monosubstituted acetylenes 1, 14, 16.…”