| Enhanced acidity of cyclopenta-2,4-dienylborane and its Al and Ga analogues. The role of aromatization. | |
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MedLine Citation:
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PMID: 20449020 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The intrinsic acidity of cyclopenta-2,4-dienylborane and its Al and Ga analogues has been compared to that of cyclopentadiene by means of B3LYP/6-311+G(3df,2p)//CCSD/6-311+G(d,p) calculations. Substitution of one of the H atoms of the C(sp(3))H(2) group of cyclopentadiene by an XH(2) (X = B, Al, Ga) leads to an acidity enhancement which is significantly large for the boron derivative (95 kJ mol(-1)); but much smaller for the Al and Ga containing analogues. This acidity enhancement reflects the stabilization of the anion, in the substituted derivatives, due to a significant reinforcement of the C-X bond. This enhancement is however smaller than expected because, although XH(2) (X = B, Al, Ga) substitution leads to a significant aromatization of the neutral compounds, the aromaticity significantly decreases upon deprotonation, whereas for the unsubstituted parent compound is the other way around. Cyclopenta-2,4-dienylborane and its Al and Ga analogues behave as highly fluxional systems. |
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Authors:
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Marcela Hurtado; Manuel Yáñez; Jean-Claude Guillemin |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2009-07-27 |
Journal Detail:
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Title: Physical chemistry chemical physics : PCCP Volume: 11 ISSN: 1463-9084 ISO Abbreviation: Phys Chem Chem Phys Publication Date: 2009 Oct |
Date Detail:
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Created Date: 2010-05-07 Completed Date: 2010-08-09 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 100888160 Medline TA: Phys Chem Chem Phys Country: England |
Other Details:
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Languages: eng Pagination: 8759-66 Citation Subset: IM |
Affiliation:
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Departamento de Química, C-9. Universidad Autónoma de Madrid, Cantoblanco, 28049-Madrid, Spain. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Acids
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chemistry* Aluminum / chemistry* Computer Simulation Cyclopentanes / chemistry* Gallium / chemistry* Models, Chemical |
| Chemical | |
Reg. No./Substance:
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0/Acids; 0/Cyclopentanes; 0/cyclopenta-2,4-dienylborane; 7429-90-5/Aluminum; 7440-55-3/Gallium |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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