A DFT Study of the Thermal, Orbital Symmetry Forbidden, Cyclophanediene to Dihydropyrene Electrocyclic Reaction. Predictions to Improve the Dimethyldihydropyrene Photoswitches.
The orbital symmetry forbidden thermal electrocyclic equilibria between a series of cyclophanedienes and dimethyldihydropyrenes (CPDs→←DDPs) were studied using density functional theory (DFT). These reactions are important not only because of their fundamental interest but also in how they restrict...
| Publicado en: | Journal of the American Chemical Society Vol. 127; no. 46; pp. 16207 - 16215 |
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| Autores principales: | , , , |
| Formato: | Artículo |
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American Chemical Society
11/23/2005
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| 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=19296894&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 19296894 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: 11/23/2005 vid: 127 iid: 46 pid: 997 pub: American Chemical Society artinfo: ui: 19296894 10.1021/ja054553r ppf: 16207 ppct: 8 formats: tig: atl: A DFT Study of the Thermal, Orbital Symmetry Forbidden, Cyclophanediene to Dihydropyrene Electrocyclic Reaction. Predictions to Improve the Dimethyldihydropyrene Photoswitches. aug: au: Williams, Richard Vaughan Edwards, W. Daniel Mitchell, Reginald H. Robinsont, Stephen G. affil: Department of Chemistry, University of Idaho, PO Box 442343, Moscow, Idaho 83844-2343. Department of Chemistry, University of Victoria, PO Box 3065, Victoria, BC, Canada V8W 3V6. su: Density functionals Conservation of orbital symmetry Cyclophanes Pyrene Symmetry (Physics) Conformational analysis Methyl groups sug: subj: Density functionals Conservation of orbital symmetry Cyclophanes Pyrene Symmetry (Physics) Conformational analysis Methyl groups ab: The orbital symmetry forbidden thermal electrocyclic equilibria between a series of cyclophanedienes and dimethyldihydropyrenes (CPDs→←DDPs) were studied using density functional theory (DFT). These reactions are important not only because of their fundamental interest but also in how they restrict the potential utility of the DDP photoswitches by limiting the thermal lifetime of the CPDs. The transition states (TS5) for these reactions could not be modeled using restricted OFT (RB3LYP) but were located using unrestricted OFT (UB3LYP). Each TS possesses significant biradical character as indicated by their spin contaminated wave functions, (S²) ≠ 0. Specific substitution by nitrile or trifluoromethyl group(s) is predicted to strongly affect the magnitude of the activation barriers for these reactions. In particular, replacing the internal methyl groups of the CPDs/ODPs with nitrile groups is predicted to have the maximum effect and to raise the activation barriers and lifetimes of the CPDs considerably. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2005 holdings: @attributes: islocal: N |
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