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dc.contributor.authorShunichi Fukuzumi-
dc.contributor.authorKei Okubo-
dc.date.accessioned2016-08-27T04:08:41Z-
dc.date.available2016-08-27T04:08:41Z-
dc.date.issued2015-
dc.identifier.issn0002-7863-
dc.identifier.otherOAK-16209-
dc.identifier.urihttp://dspace.ewha.ac.kr/handle/2015.oak/217927-
dc.description.abstractPhoto excitation of end-on trans-mu-1,2-peroxodicopper(II) complex [(tmpa)(2)Cu-2(II)(O-2)](2+) (1) (lambda(max) = 525 and 600 nm) and side-on mu-eta(2):eta(2)-peroxodicopper(II) complexes [(NS)Cu-2(II)(O-2)](2+) (2) and [(N3)Cu-2(II)(O-2)](2+) (3) at -80 degrees C in acetone led to one-photon two-electron peroxide-to-dioxygen oxidation chemistry (O-2(2-) + hv -> O-2 + 2e(-)). Interestingly, light excitation of 2 and 3 (having side-on mu-eta(2):eta(2)-peroxo ligation) led to release of dioxygen, while photoexcitation of 1 (having an end-on trans-1,2-peroxo geometry) did not, even though spectroscopic studies revealed that both reactions proceeded through previously unknown mixed-valent superoxide species: [CuII(O-2(center dot-))Cu-I](2+) (lambda(max) = 685-740 nm). For 1, this intermediate underwent further fast intramolecular electron transfer to yield an "O-2-caged" dicopper(I) adduct, Cu-2(I)-O-2, and a barrierless stepwise back electron transfer to regenerate 1 occurred. Femtosecond laser excitation of 2 and 3 under the same conditions still led to [Cu-II(O-2(center dot-))Cu-I](2+) intermediates that, instead, underwent O-2 release with a quantum yield of 0.14 +/- 0.1 for 3. Such remarkable differences in reaction pathways likely result from the well-known ligand-derived stability of 2 and 3 vs 1 indicated by ligand-Cu-II/I redox potentials; (N5)Cu-I and (N3)Cu-I complexes are far more stable than (tmpa)Cu-I species. The fast Cu-2(I)/O-2 rebinding kinetics was also measured after photoexcitation of 2 and 3, with the results closely tracking those known for the dicopper proteins hemocyanin and tyrosinase, for which the synthetic dicopper(I) precursors [(N5)Cu-2(I)](2+) and [(N3)Cu-2(I)](2+) and their dioxygen adducts serve as models. The biological relevance of the present findings is discussed, including the potential impact on the solar water splitting process.-
dc.languageEnglish-
dc.publisherAMER CHEMICAL SOC-
dc.titleLaser-Induced Dynamics of Peroxodicopper(II) Complexes Vary with the Ligand Architecture. One-Photon Two-Electron O-2 Ejection and Formation of Mixed-Valent (CuCuII)-Cu-I-Superoxide Intermediates-
dc.typeArticle-
dc.relation.issue50-
dc.relation.volume137-
dc.relation.indexSCIE-
dc.relation.indexSCOPUS-
dc.relation.startpage15865-
dc.relation.lastpage15874-
dc.relation.journaltitleJOURNAL OF THE AMERICAN CHEMICAL SOCIETY-
dc.identifier.doi10.1021/jacs.5b10177-
dc.identifier.wosidWOS:000367562800045-
dc.identifier.scopusid2-s2.0-84952802823-
dc.author.googleSaracini, Claudio-
dc.author.googleOhkubo, Kei-
dc.author.googleSuenobu, Tomoyoshi-
dc.author.googleMeyer, Gerald J.-
dc.author.googleKarlin, Kenneth D.-
dc.author.googleFukuzumi, Shunichi-
dc.contributor.scopusidShunichi Fukuzumi(35430038100)-
dc.contributor.scopusidKei Okubo(7101788990)-
dc.date.modifydate20200403081004-
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