NMR-Based Structural Modeling of Graphite Oxide Using Multidimensional C Solid-State NMR and ab Initio Chemical Shift Calculations.
Chemically modified graphenes and other graphite–based materials have attracted growing interest for their unique potential as lightweight electronic and structural nanomaterials. It is an important challenge to construct structural models of noncrystalline graphite–based materials on the basis of N...
| Publicado en: | Journal of the American Chemical Society Vol. 132; no. 16; pp. 5672 - 5677 |
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| Autores principales: | , , , , , , |
| Formato: | Artículo |
| Publicado: |
American Chemical Society
4/28/2010
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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=50319144&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 50319144 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: 4/28/2010 vid: 132 iid: 16 pid: 997 pub: American Chemical Society artinfo: ui: 50319144 10.1021/Ja9030243 ppf: 5672 ppct: 5 formats: tig: atl: NMR-Based Structural Modeling of Graphite Oxide Using Multidimensional C Solid-State NMR and ab Initio Chemical Shift Calculations. aug: au: Casabianca, Leah B. Shaibat, Medhat A. Cai, Weiwei W. Park, Sungjin Piner, Richard Ruoff, Rodney S. Ishjj, Yoshitaka affil: Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607, UISA Department of Mechanical Engineering and the Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712, USA su: Graphene Graphite composites Nuclear magnetic resonance Anisotropy Mathematical optimization Chemical reactions sug: subj: Graphene Graphite composites Nuclear magnetic resonance Anisotropy Mathematical optimization Chemical reactions ab: Chemically modified graphenes and other graphite–based materials have attracted growing interest for their unique potential as lightweight electronic and structural nanomaterials. It is an important challenge to construct structural models of noncrystalline graphite–based materials on the basis of NMR or other spectroscopic data. To address this challenge, a solid–state NMR (SSNMR)–based structural modeling approach is presented on graphite oxide (GO), which is a prominent precursor and interesting benchmark system of modified graphene. An experimental 2D ˜3C double–quantum/single–quantum correlation SSNMR spectrum of C–labeled GO was compared with spectra simulated for different structural models using ab initio geometry optimization and chemical shift calculations. The results show that the spectral features of the GO sample are best reproduced by a geometry–optimized structural model that is based on the Lerf–Klinowski model (Lert, A. et al. Phys. Chem. B 1998, 102, 4477); this model is composed of interconnected sp, 1,2–epoxide, and COH carbons. This study also convincingly excludes the possibility of other previously proposed models, including the highly oxidized structures involving 1 ,3–epoxide carbons (Szabo, I. et al. Chem. Mater. 2006, 18, 2740). C chemical shift anisotropy (CSA) pattems measured by a 2D C CSAlisotropic shift correlation SSNMR were well reproduced by the chemical shift tensor obtained by the ab initio calculation for the former model. The approach presented here is likely to be applicable to other chemically modified graphenes and graphite–based systems. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2010 holdings: @attributes: islocal: N |
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