Tautomeric equilibria of 3-formylacetylacetone: low-temperature NMR spectroscopy and ab initio calculations.
Keto-enol tautomerization of 3-formylacetylacetone has been studied by NMR spectroscopy, ab initio, and DFT calculations in the gas phase and continuum solvation. By employing very low temperatures in a freonic solvent, tautomeric and conformational equilibria in the slow exchange regime were analyzed in detail. The beta-tricarbonyl compound always adopts a structure with an enolized keto group irrespective of an increasing dielectric constant of the solvent when lowering the temperature of the Freon mixture. This experimentally observed tautomeric distribution of 3-formylacetylacetone is correctly reproduced by continuum solvated DFT calculations.
Basílio Janke
Eline M
EM
Institut für Chemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany.
Schlund
Sebastian
S
Paasche
Alexander
A
Engels
Bernd
B
Dede
Rüdiger
R
Hussain
Ibrar
I
Langer
Peter
P
Rettig
Michael
M
Weisz
Klaus
K
D000447:Aldehydes / Q000737:chemistry*; D003500:Cyclization; D005561:Formates / Q000737:chemistry*; D005740:Gases; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D010422:Pentanones / Q000737:chemistry*; D012996:Solutions; D012997:Solvents; D013237:Stereoisomerism; D013696:Temperature
C544636:3-formylacetylacetone; D000447:Aldehydes; D005561:Formates; D005740:Gases; D010422:Pentanones; D012996:Solutions; D012997:Solvents