10.1021/jo060603e.s001
Natalya V. Belova
Natalya V.
Belova
Georgiy V. Girichev
Georgiy V.
Girichev
Sergey A. Shlykov
Sergey A.
Shlykov
Heinz Oberhammer
Heinz
Oberhammer
Tautomeric and Conformational Properties of Acetoacetamide:
Electron Diffraction and Quantum Chemical Study
American Chemical Society
2006
set
quantum chemical calculations
CH 3C
basis
GED
MP 2 approximations
gas electron diffraction
diketo
Quantum Chemical StudyThe tautomeric properties
quantum chemical method
B 3LYP method
enol
2006-07-07 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Tautomeric_and_Conformational_Properties_of_Acetoacetamide_Electron_Diffraction_and_Quantum_Chemical_Study/3072028
The tautomeric properties of acetoacetamide, CH<sub>3</sub>C(O)CH<sub>2</sub>C(O)NH<sub>2</sub>, have been investigated by gas
electron diffraction (GED) and quantum chemical calculations (B3LYP and MP2 approximations with
6-31G(d,p) and 6-311++G(3df,pd) basis sets). GED results in a mixture of 63(7)% enol tautomer and
37(7)% diketo form at 74(5) °C. Only one enol form with the O−H bond adjacent to the methyl group
(CH<sub>3</sub>C(OH)CHC(O)NH<sub>2</sub>) and only one diketo conformer (with dihedral angles τ(OC(CH<sub>3</sub>)CC)
= 31.7(7.5)° and τ(OC(NH<sub>2</sub>)C(H<sub>2</sub>)C(O)) = 130.9(4.5)°) are present. The calculated tautomeric
composition varies in a wide range depending on the quantum chemical method and basis set. Only the
B3LYP method with small basis sets reproduces the experimental compositon correctly.