Reactions of 10-methyl-9,10-dihydroacridine with inorganic oxidants
dc.contributor.advisor | James H. Espenson | |
dc.contributor.author | Pestovsky, Oleg | |
dc.contributor.department | Chemistry | |
dc.date | 2018-08-23T12:47:11.000 | |
dc.date.accessioned | 2020-06-30T07:16:31Z | |
dc.date.available | 2020-06-30T07:16:31Z | |
dc.date.copyright | Thu Jan 01 00:00:00 UTC 1998 | |
dc.date.issued | 1998 | |
dc.description.abstract | <p>Reactions of 10-methyl-9,10-dihydroacridine with various inorganic oxidants in 20% acetonitrile/80% water solvent mixture fall into two categories depending on the strength of the oxidant used. Rapid electron transfer to the strong oxidizing reagents, Ce IV and IrCl62-, produces dihydroacridine radical cations, AcrH2·+ ([lambda] max 650 nm). This is followed by the rate-determining loss of a proton and rapid oxidation of thus formed AcrH· by the second equivalent of Ce IV or IrCl62-. The protonation of AcrH· and deprotonation of AcrH2·+ exhibit significant kinetic isotope effects. The use of d2-acridine in H2O/CH3CN yields the secondary and solvent isotope effects separately. A large normal secondary isotope effect of 1.86 ± 0.17 for the protonation of the acridinium radical suggests a possibility of nuclear tunneling. The reaction of dihydroacridine with a mild oxidizing reagent, Fe3+, is slow and shows no kinetic isotope effect. The initial electron transfer from AcrH2 to Fe3+ is believed to be rate-determining;The oxidation of AcrH2 to AcrH+ by hydrogen chromate ions is a chain reaction that is strongly inhibited by oxygen. The initiation reaction between AcrH2 or AcrD2 and H2CrO4 forms AcrH2·+ and occurs by a 1e mechanism, kH = kD = 4.6x102 L mol-1s-1 (25°C). The Cr V produced along with AcrH· (from the acid ionization of AcrH2·+ are chain-carrying intermediates. The propagating reaction between AcrH2 and Cr V, k = 1 x 108 L mol-1s-1, is of key importance since it is a branching reaction that yields two chain carriers, AcrH· and CrO2+, by hydrogen atom abstraction. The same partners react competitively by hydride ion abstraction, to yield Cr3+ and AcrH+, k = 1.2 x 107 L mol-1 s-1, in the principal termination step. The reaction of CrO2+ and AcrH2, kH = 1.0 x 104 and kD = 4.8 x 103 L mol-1 s-1, proceeds by hydride ion transfer. The Cr2+ so produced could be trapped as CrOO2+ when O2 was present, thereupon terminating the chain. AcrH2 itself reacts with Cr2O72- + H+, k = 5.6 x 103 L2 mol-2s-1, but this step is not an initiating reaction. From that, two successive electron transfer steps are believed to occur, yielding CrIV + CrVI + AcrH+.</p> | |
dc.format.mimetype | application/pdf | |
dc.identifier | archive/lib.dr.iastate.edu/rtd/11881/ | |
dc.identifier.articleid | 12880 | |
dc.identifier.contextkey | 6510377 | |
dc.identifier.doi | https://doi.org/10.31274/rtd-180813-10802 | |
dc.identifier.s3bucket | isulib-bepress-aws-west | |
dc.identifier.submissionpath | rtd/11881 | |
dc.identifier.uri | https://dr.lib.iastate.edu/handle/20.500.12876/65187 | |
dc.language.iso | en | |
dc.source.bitstream | archive/lib.dr.iastate.edu/rtd/11881/r_9841076.pdf|||Fri Jan 14 19:00:15 UTC 2022 | |
dc.subject.disciplines | Inorganic Chemistry | |
dc.subject.keywords | Chemistry | |
dc.subject.keywords | Inorganic chemistry | |
dc.title | Reactions of 10-methyl-9,10-dihydroacridine with inorganic oxidants | |
dc.type | article | |
dc.type.genre | dissertation | |
dspace.entity.type | Publication | |
relation.isOrgUnitOfPublication | 42864f6e-7a3d-4be3-8b5a-0ae3c3830a11 | |
thesis.degree.level | dissertation | |
thesis.degree.name | Doctor of Philosophy |
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