Tautomeric properties and gas-phase structure of acetylacetone.
The tautomeric and structural properties of acetylacetone, CH3C(O)CH2C(O)CH3, have been studied by gas-phase electron diffraction (GED) and quantum chemical calculations (B3LYP and MP2 approximation with different basis sets up to aug-cc-pVTZ). The analysis of GED intensities resulted in the presence of 100(3)% of the enol tautomer at 300(5) K and 64(5)% of the enol at 671(7) K. The enol tautomer possesses Cs symmetry with a planar ring and strongly asymmetric hydrogen bond. The diketo form possesses C2 symmetry. The experimental geometric parameters of both tautomeric forms are reproduced very closely by B3LYP/aug-cc-pVTZ and MP2/cc-pVTZ methods.
Research Institute for Thermodynamics and Kinetics of Chemical Processes, Ivanovo State University of Chemistry and Technology , 153460 Ivanovo, Russia.
Natalya V
NV
Belova
Heinz
H
Oberhammer
Nguen Hoang
NH
Trang
Georgiy V
GV
Girichev