Abstract
Ionization of the well-known 2:1 dimedone-aldehyde adducts in polar solvents leads to the respective monoanions involving the intramolecular ionic hydrogen bond. These anions feature the short O⋯Ha⋯O distance (2.403 Å for 4, R=p-ClC6H4) and the strong downfield shift of the corresponding signal (δHa = 17.0 ppm, in dichloromethane-d2). The negative charge is delocalized over the two dimedone moieties. This phenomenon is also reproduced by quantum mechanical calculations. The dynamic NMR spectra provide an estimate of the hydrogen bond energy as high as 16 kcal/mol.
Original language | English |
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Pages (from-to) | 230-236 |
Number of pages | 7 |
Journal | Journal of Molecular Structure |
Volume | 977 |
Issue number | 1-3 |
DOIs | |
State | Published - 10 Aug 2010 |
Keywords
- Dynamic NMR
- Ionic hydrogen bonds
- Theoretical calculations
ASJC Scopus subject areas
- Analytical Chemistry
- Spectroscopy
- Organic Chemistry
- Inorganic Chemistry