| Autor: |
Tanaka, Minoru, Shono, Toshiyuki, Shinra, Koichiro |
| Zdroj: |
Bulletin of the Chemical Society of Japan; November 1969, Vol. 42 Issue: 11 p3190-3194, 5p |
| Abstrakt: |
Seventeen 3-substituted-2,4-pentanediones were synthesized. The effect of substituents in the position 3 on the tautomeric equilibria, i.e., keto-, cis-enol- and trans-enol-forms, has been investigated by nuclear magnetic resonance spectroscopy. It has been found that the percentage of each tautomer depends upon the electronic and steric effects of the substituents. The relative intensity of intramolecular hydrogen bonds in these compounds was evaluated from both the NMR and IR data. It has been found from the half-wave potential data of polarographic reduction and the Cu–O stretching frequencies of 16 copper chelates of 3-substituted-2,4-pentanediones that the relative stability of the chelate decreases with an increase in the electron-withdrawing effect of the substituents. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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