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dc.contributor.authorAlemayehu, Abraham
dc.contributor.authorMcCormick, Laura J
dc.contributor.authorVazquez Lima, Hugo
dc.contributor.authorGhosh, Abhik
dc.date.accessioned2020-04-28T10:17:20Z
dc.date.available2020-04-28T10:17:20Z
dc.date.issued2019-02-07
dc.description.abstractA series of metal–metal bonded osmium corrole dimers, {Os[TpXPC]}2, were synthesized in reasonably good yields (35–46%) via the interaction of the corresponding free-base meso-tris(p-X-phenyl)corroles (H3[TpXPC], X = CF3, H, CH3, and OCH3), Os3(CO)12, and potassium carbonate in 1,2,4-trichlorobenzene under an inert atmosphere at 180 °C over several hours. The complexes are only the second class of Os corroles reported to date (the first being OsVIN corroles) and also the second class of metal–metal bonded metallocorrole dimers (the other being Ru corrole dimers). Comparison of the X-ray structures, redox potentials, and optical spectra of analogous Ru and Os corrole dimers, along with scalar-relativistic DFT calculations, has provided an experimentally calibrated account of relativistic effects in these complexes. Three of the Os corrole dimers (X = CF3, H, and OCH3) were analyzed with single-crystal X-ray diffraction analysis, revealing inversion-related corrole rings with eclipsed Os–N bonds and Os–Os distances of ∼2.24 Å that are ∼0.06 Å longer than the Ru–Ru distances in the analogous Ru corrole dimers. Interestingly, a comparison of scalar-relativistic and nonrelativistic DFT calculations indicates that this difference in metal–metal bond distance does not, in fact, reflect a differential relativistic effect. For a given corrole ligand, the Ru and Os corrole dimers exhibit nearly identical oxidation potentials but dramatically different reduction potentials, with the Os values ∼0.5 V lower relative to Ru, suggesting that whereas oxidation occurs in a ligand-centered manner, reduction is substantially metal-centered, which indeed was confirmed by scalar-relativistic calculations. The calculations further indicate that approximately a third of the ∼0.5 V difference in reduction potentials can be ascribed to relativity. The somewhat muted value of this relativistic effect appears to be related to the finding that reduction of an Os corrole dimer is not exclusively metal-based but that a significant amount of spin density is delocalized over to the corrole ligand; in contrast, reduction of an Ru corrole dimer occurs exclusively on the Ru–Ru linkage. For isoelectronic complexes, the Ru and Os corrole dimers exhibit substantially different UV–vis spectra. A key difference is a strong near-UV feature of the Os series, which in energy terms is blue-shifted by ∼0.55 V relative to the analogous feature of the Ru series. TDDFT calculations suggest that this difference may be related to higher-energy Os(5d)-based LUMOs in the Os case relative to analogous MOs for Ru.en_US
dc.descriptionPublisher's statement (option C): <a href=https://pubs.acs.org/page/4authors/authorchoice/options.html> https://pubs.acs.org/page/4authors/authorchoice/options.html</a>en_US
dc.identifier.citationAlemayehu, A,; McCormick, L.J.; Vazquez Lima, H.; Ghosh, A.(2019) Relativistic Effects on a Metal-Metal Bond: Osmium Corrole Dimers.<i> Inorganic Chemistry, 58,</i> (4), 2798-2806en_US
dc.identifier.cristinIDFRIDAID 1699148
dc.identifier.doi10.1021/acs.inorgchem.8b03391
dc.identifier.issn0020-1669
dc.identifier.issn1520-510X
dc.identifier.urihttps://hdl.handle.net/10037/18144
dc.language.isoengen_US
dc.publisherACS Publicationsen_US
dc.relation.journalInorganic Chemistry
dc.relation.projectIDNorges forskningsråd: 262229en_US
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright © 2019 American Chemical Societyen_US
dc.subjectVDP::Mathematics and natural science: 400::Chemistry: 440en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Kjemi: 440en_US
dc.titleRelativistic Effects on a Metal-Metal Bond: Osmium Corrole Dimersen_US
dc.type.versionacceptedVersionen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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