Show simple item record

dc.contributor.authorJeong, Hyangsoo
dc.contributor.authorJohn, Jeremy M
dc.contributor.authorSchrock, Richard Royce
dc.date.accessioned2016-11-03T18:28:58Z
dc.date.available2016-11-03T18:28:58Z
dc.date.issued2015-10
dc.identifier.issn0276-7333
dc.identifier.issn1520-6041
dc.identifier.urihttp://hdl.handle.net/1721.1/105182
dc.description.abstractRing-opening metathesis polymerization (ROMP) is used to prepare trans-poly(A-alt-B) polymers from a 1:1 mixture of A and B where A is a cyclic olefin such as cyclooctene (A[subscript 1]) or cycloheptene (A[subscript 2]) and B is a large norbornadiene or norbornene derivative such as 2,3-dicarbomethoxy-7-isopropylidenenorbornadiene (B[subscript 1]) or dimethylspirobicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate-7,1'cyclopropane (B[subscript 2]). The most successful initiators that were examined are of the type Mo(NR)(CHCMe[subscript 2]Ph)[OCMe(CF[subscript 3])[subscript 2]][subscript 2] (R = 2,6-Me[subscript 2]C[subscript 6]H[subscript 3] (1) or 2,6-iPr[subscript 2]C[subscript 6]H[subscript 3] (2)). The trans configuration of the AB linkages is proposed to result from the steric demand of B. Both anti-MB and syn-MB alkylidenes are observed during the copolymerization, where B was last inserted into a Mo=C bond, although anti-MB dominates as the reaction proceeds. Anti-MB is lower in energy than syn-MB, does not react readily with either A or B, and interconverts slowly with syn-MB through rotation about the Mo=C bond. Syn-MB does not readily react with B, but it does react slowly with A (rate constant ~1 M[superscript -1] s [superscript -1]) to give anti-MA and one trans-AB linkage. Anti-MA then reacts with B (rate constant ~300 M[superscript -1] s[superscript -1] or larger) to give syn-MB and the second trans-AB linkage. The reaction has been modeled using experimental data in order to obtain the estimated rate constants above. The reaction between anti-MA and A is proposed to give rise to AA linkages, but AA dyads can amount to <5%. Several other possible A and B monomers, initiators, and conditions were explored.en_US
dc.description.sponsorshipUnited States. Dept. of Energy (Grant DE-FG02-86ER13564)en_US
dc.language.isoen_US
dc.publisherAmerican Chemical Society (ACS)en_US
dc.relation.isversionofhttp://pubs.acs.org/doi/full/10.1021/acs.organomet.5b00709en_US
dc.rightsArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.en_US
dc.sourceProf. Schrocken_US
dc.titleFormation of Alternating trans-A-alt-B Copolymers through Ring-Opening Metathesis Polymerization Initiated by Molybdenum Imido Alkylidene Complexesen_US
dc.typeArticleen_US
dc.identifier.citationJeong, Hyangsoo, Jeremy M. John, and Richard R. Schrock. “Formation of Alternating trans-A-alt-B Copolymers through Ring-Opening Metathesis Polymerization Initiated by Molybdenum Imido Alkylidene Complexes.” Organometallics 34.20 (2015): 5136–5145.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Chemistryen_US
dc.contributor.approverSchrock, Richard Royceen_US
dc.contributor.mitauthorJeong, Hyangsoo
dc.contributor.mitauthorJohn, Jeremy M
dc.contributor.mitauthorSchrock, Richard Royce
dc.relation.journalOrganometallicsen_US
dc.eprint.versionAuthor's final manuscripten_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dspace.orderedauthorsJeong, Hyangsoo; John, Jeremy M.; Schrock, Richard R.en_US
dspace.embargo.termsNen_US
dc.identifier.orcidhttps://orcid.org/0000-0002-1788-4100
dc.identifier.orcidhttps://orcid.org/0000-0002-7405-6811
dc.identifier.orcidhttps://orcid.org/0000-0001-5827-3552
mit.licensePUBLISHER_POLICYen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record