Ring-opening metathesis polymerization of substituted cyclopropenes
Abstract/Contents
- Abstract
- Life would not be possible without precise macromolecular sequence control. The ability of biological systems to encode information, transmit instructions, and catalyze chemical reactions relies on the proper ordering of monomeric units. While our synthetic capabilities may trail those nature has developed through billions of years of evolution, continued advances in polymer science have allowed ever greater control over polymer microstructures. Specifically, living polymerization techniques, such as ring-opening metathesis polymerization (ROMP), have given us the tools to synthesize polymers with defined molecular weights and narrow molecular weight distributions. While ROMP is typically driven by the release of ring strain, surprisingly little research has been performed on the polymerization of cyclopropenes (CPEs), the monocyclic olefin with the highest ring strain. We believed that the high strain energy of this class of monomers along with the ability to tune the steric environment through strategic substitutions would result in unique reactivity and potential to control monomer sequences. In building a library of CPEs capable of ROMP, we discovered a unique class of CPEs that only singly added to Grubbs third generation catalyst followed by no further homopolymerization. We have used this behavior to develop a system for perfectly alternating ROMP with CPEs and low-strain cyclic olefins. Further investigations have shown that this technique can be extended to incorporate other low-strain cycles, allowing for functionalities to be directly incorporated into the polymer backbone. Additionally, with these molecules in hand, we have been able to incorporate single functional units into a polymer backbone by addition of precisely one equivalent of monomer relative to catalyst. At first using this technique to synthesize telechelic polymers, we have successfully optimized this system to allow the incorporation of exactly one monomer into a ROMP polymer at any defined location along the backbone, giving unprecedented control over polymer sequence using via solution chemistry.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2018; ©2018 |
| Publication date | 2018; 2018 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Elling, Benjamin Ross |
|---|---|
| Degree supervisor | Xia, Yan, 1980- |
| Thesis advisor | Xia, Yan, 1980- |
| Thesis advisor | Burns, Noah |
| Thesis advisor | Waymouth, Robert M |
| Degree committee member | Burns, Noah |
| Degree committee member | Waymouth, Robert M |
| Associated with | Stanford University, Department of Chemistry. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Benjamin Ross Elling. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis Ph.D. Stanford University 2018. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2018 by Benjamin Ross Elling
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