Dissertation/Thesis Abstract

Ring-Opening Alkyne Metathesis Methods for Functional Conjugated Polymer Synthesis
by von Kugelgen, Stephen W., Ph.D., University of California, Berkeley, 2018, 229; 13423664
Abstract (Summary)

Since its discovery in the mid 20th century, most applications of alkyne metathesis have relied on thermodynamics to control product distributions. Ring-opening alkyne metathe- sis polymerization (ROAMP), in contrast, requires the kinetic product of metathesis of a strained, cyclic alkyne monomer to give a living, chain-growth polymerization (Chapter 1, Introduction). This living polymerization of conjugated alkyne-containing monomers has the potential to access a wide range of functional poly(arylene ethynylene) materials with excep- tional control over length, dispersity, topology, and endgroups. To this end, we demonstrate the first ROAMP synthesis of conjugated poly(ortho-phenylene ethynylene) and elucidate a mechanistic description of the reaction to understand the enabling catalyst selectivity and unexpectely find that initiator sterics dictate endgroup fidelity and polymer topology (Chap- ter 2). To disentangle the role of steric and electronic factors in initiator performance, we describe a novel synthetic method that gives a series of isosteric benzylidyne catalysts which exhibit a strong, deterministic electronic effect on both ROAMP initiation rates and polymer endgroup fidelity (Chapter 3). Finally, we develop an extension of this methodology to lever- age the alkynes from these living polymers to template the synthesis of telechelic graphene nanoribbons (GNRs) (Chapter 4). This work has not only uncovered mechanistic insights and design principles to improve ROAMP catalysts and facilitate access to hybrid poly- mer materials, but also demonstrated the potential of ROAMP to access other conjugated materials via post-polymerization modification of precision polymer templates.

Indexing (document details)
Advisor: Fischer, Felix R.
Commitee: Bergman, Robert G., Messersmith, Phillip B.
School: University of California, Berkeley
Department: Chemistry
School Location: United States -- California
Source: DAI-B 80/08(E), Dissertation Abstracts International
Subjects: Chemistry, Inorganic chemistry, Polymer chemistry
Keywords: Alkyne metathesis, Graphene nanoribbons, Living polymerization, Organometallic chemistry, Physical organic chemistry, Polymer semiconductors
Publication Number: 13423664
ISBN: 978-1-392-03623-5
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