Reaction paths of the water-assisted solvolysis of N,N-dimethylformamide.
J Phys Chem A
; 111(28): 6296-303, 2007 Jul 19.
Article
en En
| MEDLINE
| ID: mdl-17580828
Density functional theory calculations were conducted on the title reactions with explicit inclusion of a variety of water molecules, H-CO-NMe2+MeOH+(H2O)n-->H-CO-OMe+HNMe2+(H2O)n. Geometries of transition states, reactant-like complexes and product-like ones were determined by the use of RB3LYP/6-31G(d) SCRF=dipole. Concerted paths were examined with n=0-3. Their Gibbs activation energies are larger than the experimental value. Stepwise paths were also investigated with n=2-4. The n=4 model has the energy close to the experimental value. However, when the catalytic water molecules were added to the n=4 one, the stepwise path was switched to the concerted one. A systematic comparison of the concerted path with n=2+1, 2+2, 2+3, 2+4, 2+5, 2+4+4, and 2+5+5 models was made, and the water-dimer based reaction path was found to be most favorable. The contrast between the concerted path of the amide solvolysis (and hydrolysis) and the stepwise one of the ester hydrolysis was discussed in terms of the frontier-orbital theory.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Agua
/
Modelos Moleculares
/
Dimetilformamida
/
Modelos Químicos
Idioma:
En
Revista:
J Phys Chem A
Asunto de la revista:
QUIMICA
Año:
2007
Tipo del documento:
Article
País de afiliación:
Japón
Pais de publicación:
Estados Unidos