Oxygen Atom Transfer Reactions of Chromium Porphyrins: An Electronic Rationale for Oxo Transfer versus μ-Oxo Product Formation

dc.contributor.author Woo, L. Keith
dc.contributor.author Goll, James
dc.contributor.author Woo, L.
dc.contributor.author Berreau, Lisa
dc.contributor.author Weaving, Rob
dc.contributor.department Chemistry
dc.date 2018-02-17T09:17:14.000
dc.date.accessioned 2020-06-30T01:22:27Z
dc.date.available 2020-06-30T01:22:27Z
dc.date.copyright Wed Jan 01 00:00:00 UTC 1992
dc.date.issued 1992-09-01
dc.description.abstract <p>Treatment of (meso-tetra-p-tolylporphyrinato)chromium(IV) oxide, {TTP)Cr=O, with (octaethylporphyrinato)chromium( III) chloride, (OEP)Cr-Cl, in benzene results in the reversible exchange of axial ligands to form (TTP)Cr-Cl and (OEP)Cr=O. The net result is a formal one-electron redox process. This occurs with a second-order rate constant of 0.14 :1:: 0.01 M-1 s-1 to form an equilibrium mixture with K = 2.7 :1:: 0.1 at 30 °C (ill/* = 15.4 :1:: 0.7 kcaljmol, M* = -12 :1:: 2 cal/ (mol·K), ill/0 = -2.0 :1:: 0.4 kcaljmol, and M 0 = -4.6 :1:: 1.2 cal/ (mol·K)). Use of pivalate in place of chloride on the Cr(III) complex causes no significant change in the rate of this one-electron redox process. The sterically protected Baldwin's C2-capped {porphyrinato)chromium(III) complex, (CAP)Cr-Cl, also undergoes oxygen atom transfer with (OEP)Cr=O at a similar rate. In addition, excess chloride inhibits the rate of oxygen transfer with chlorochromium(III) complexes. These results support an inner-sphere mechanism involving a ~-oxo intermediate which is formed after an initial ligand (chloride or pivalate) dissociation from the chromium(III) reductant.</p>
dc.description.comments <p>Reprinted (adapted) with permission from <em>Journal of the American Chemical Society </em>114 (1992): 7411, doi:<a href="http://dx.doi.org/10.1021/ja00045a012" target="_blank">10.1021/ja00045a012</a>. Copyright 1992 American Chemical Society.</p>
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dc.identifier archive/lib.dr.iastate.edu/chem_pubs/730/
dc.identifier.articleid 1728
dc.identifier.contextkey 7961623
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath chem_pubs/730
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/15217
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/chem_pubs/730/0-L_1992_Woo_OxygenAtom.pdf|||Sat Jan 15 01:46:12 UTC 2022
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dc.source.uri 10.1021/ja00045a012
dc.subject.disciplines Chemistry
dc.title Oxygen Atom Transfer Reactions of Chromium Porphyrins: An Electronic Rationale for Oxo Transfer versus μ-Oxo Product Formation
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication d17ef200-84b4-46b1-94f3-67cc67f0a33f
relation.isOrgUnitOfPublication 42864f6e-7a3d-4be3-8b5a-0ae3c3830a11
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