13C and 15N NMR spectra of aminobenzimidazoles in solution and in the solid state.
The (13)C [hexadeutero-dimethylsulfoxide (DMSO-d(6)), hexamethyl-phosphoramide (HMPA)-d(18)and solid-state] and (15)N (solid-state) NMR spectra of six C-aminobenzimidazoles have been recorded. The tautomerism of 4(7)-aminobenzimidazoles and 5(6)-aminobenzimidazoles has been determined and compared with B3LYP/6-311 + + G(d,p) calculations confirming the clear predominance of the 4-amino tautomer and the slight preference for the 6-amino tautomer. GIAO-calculated absolute shieldings compare well with experimental chemical shifts.
Angeles García
M
M
Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias, UNED, Senda del Rey 9, E-28040 Madrid, Spain. magarcia@bec.uned.es
Claramunt
Rosa M
RM
Solcan
Tomás
T
Milata
Viktor
V
Alkorta
Ibon
I
Elguero
José
J