Assessment of the Electronic Factors Determining the Thermodynamics of "Oxidative Addition" of C-H and N-H Bonds to Ir(I) Complexes.
A study of electronic factors governing the thermodynamics of C-H and N-H bond addition to Ir(I) complexes was conducted. DFT calculations were performed on an extensive series of trans-(PH)IrXL complexes (L = NH and CO; X = various monodentate ligands) to parametrize the relative σ- and π-donating/...
| Publicado en: | Journal of the American Chemical Society Vol. 138; no. 1; pp. 149 - 164 |
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| Autores principales: | , , , , , |
| Formato: | Artículo |
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American Chemical Society
1/13/2016
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=113302223&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 113302223 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 1/13/2016 vid: 138 iid: 1 pid: 997 pub: American Chemical Society artinfo: ui: 113302223 10.1021/jacs.5b09522 ppf: 149 ppct: 15 formats: tig: atl: Assessment of the Electronic Factors Determining the Thermodynamics of "Oxidative Addition" of C-H and N-H Bonds to Ir(I) Complexes. aug: au: Wang, David Y. Choliy, Yuriy Haibac, Michael C. Hartwig, John F. Krogh-Jespersen, Karsten Goldman, Alan S. affil: Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903, United States Department of Chemistry, University of California, Berkeley, Berkeley, California 94720-1460, United State su: Carbon-hydrogen bonds Thermodynamics Density functional theory Methane analysis Regression analysis Ligands (Chemistry) sug: subj: Carbon-hydrogen bonds Thermodynamics Density functional theory Methane analysis Regression analysis Ligands (Chemistry) ab: A study of electronic factors governing the thermodynamics of C-H and N-H bond addition to Ir(I) complexes was conducted. DFT calculations were performed on an extensive series of trans-(PH)IrXL complexes (L = NH and CO; X = various monodentate ligands) to parametrize the relative σ- and π-donating/withdrawing properties of the various ligands, X. Computed energies of oxidative addition of methane to a series of three- and four-coordinate Ir(I) complexes bearing an ancillary ligand, X, were correlated with the resulting (σ, π) parameter set. Regression analysis indicates that the thermodynamics of addition of methane to trans-(PH)IrX are generally strongly disfavored by increased σ-donation from the ligand X, in contradiction to widely held views on oxidative addition. The trend for oxidative addition of methane to four-coordinate Ir(I) was closely related to that observed for the three-coordinate complexes, albeit slightly more complicated. The computational analysis was found to be consistent with the rates of reductive elimination of benzene from a series of isoelectronic Ir(III) phenyl hydride complexes, measured experimentally in this work and previously reported. Extending the analysis of ancillary ligand energetic effects to the oxidative addition of ammonia to three-coordinate Ir(I) complexes leads to the conclusion that increasing σ-donation by X also disfavors oxidative addition of N-H bonds to trans-(PH)IrX. However, coordination of NH to the Ir(I) center is disfavored even more strongly by increasing σ-donation by X, which explains why the few documented examples of H-NH oxidative addition to transition metals involve complexes with strongly σ-donating ligands situated trans to the site of addition. An orbital-based rationale for the observed results is presented. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2016 holdings: @attributes: islocal: N |
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