Cyclic polymers do not contain end groups, and as a result they demonstrate a number of unique physical properties. For example, the density, refractive index, Tg, viscoelasticity, reptation, and surface properties of cyclic polymers all differ from those of their more common linear analogs. Semi-conducting cyclic polymers are rare and their topological dependent properties are not well-understood. Employing a W-catalyst featuring a tetraanionic pincer ligand, semi-conducting cyclic polymers are synthesized from alkynes. Using acetylene, cyclic polyacetylene is synthesized for the first time. Dynamic and static light scattering techniques provide &lt;Rg2&gt; and RH ratios of cyclic vs. linear samples that clearly indicate a difference in topology. Complementing the light scattering data, intrinsic viscosities measured over a wide-range of molecular weights clearly demonstrate the topological relationship between authentic linear and cyclic samples. Electrical resistance measurements using a 4-point probe on thin films of linear and cyclic polymers is used to compare the effects of chain-ends.

Semi-conducting cyclic polymers and their p-doped derivatives

Macromolecular Chemistry: The Second Century

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ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.