Electro-Induced Early Transition Metal Metathesis Catalyst Systems for the Production of Polyacetylene

Abstract

The use of electro-induced Mo and W-based catalysts has been investigated in the ring opening metathesis polymerization (ROMP) of 1,3,5,7-cyclooctatetraene (COT). The soluble and conjugated polyacetylene (PA) was obtained under ambient temperature and pressure without employing any secondary reagent (comonomer, chain transfer agent) or substituted monomer (R-COT). NMR analysis results show that the electrochemical Mo-based system leads to a completely (100%) trans product, however, mainly (80%) trans polymer was obtained with W-based analogue for PA.KEY WORDS: Ring Opening Metathesis Polymerization (ROMP) / 1,3,5,7-Cyclooctatetraene (COT) / Polyacetylene (PA) / Transition Metal Catalyst / Electrochemistry / Conjugated polymers, the simplest being polyacetylene, are of current interest because the substantial electronic delocalization along their backbones gives rise to interesting optical and nonlinear optical properties and allows them to become good electrical conductors. These properties might lead to a variety of applications including optical signal processing and information storage, lightweight substitutes for metals in batteries and materials for solar energy conversion.

Reactions of an anionic chelate phosphane/borata-alkene ligand with [Rh(nbd)Cl]2, [Rh(CO)2Cl]2 and [Ir(cod)Cl]2

“…25 a We also polymerized p -fluorophenylacetylene and p -methoxyphenylacetylene at the catalyst system 12 (0.1 mol%) and isolated the respective polyacetylenes in close to quantitative yields ( Scheme 7 ). 26 …”