Chemical and Spectroscopic Studies Related to the Lewis Acidity of Lithium Perchlorate in Diethyl Ether
| Autor: | James F. Green, Kevin F. West, Martin Chandler, George W. Kabalka, David Boyles, Chanda Elam, Craig Bowe, Richard M. Pagni, Gerald Springer, Anna G. Edwards, John E. Bartmess, Jan R. Williams |
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| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | The Journal of Organic Chemistry. 64:2202-2210 |
| ISSN: | 1520-6904 0022-3263 |
| DOI: | 10.1021/jo981042x |
| Popis: | Polarimetric studies on camphor (2) as well as IR studies on crotonaldehyde (CA; 1) and benzonitrile (BN; 3) confirm the conclusion of a previously published NMR study on crotonaldehyde that lithium perchlorate (LP) weakly binds to probe bases in diethyl ether (DE). The weak binding is a consequence of the fact that the lithium ion (actually the LP ion pair and higher aggregates), a powerful Lewis acid in the gas phase, competitively binds to ether and the added base. Methylene camphor (5), (E)-1,3-pentadiene (4), camphene, and phenylacetylene (6) do not bind to LP in DE. Shifts to lower energy of the CO modes of CA in ether solutions containing increasing amounts of LP are consistent with moderate increases in solvent polarity. Only small or no shifts are seen in the C⋮N modes of BN and its 1:1 complex with added LP. Because the C⋮N and especially CO modes are blue shifted under external applied pressure, the large internal pressures of LP/DE do not mimic external applied pressure. Likewise, the small or... |
| Databáze: | OpenAIRE |
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