Tautomerism in the solid state and in solution of a series of 6-aminofulvene-1-aldimines.
To study systems able to sustain intramolecular proton-transfer, we have prepared a series of six aminofulvene aldimines including several labeled with (15)N and (2)H. These compounds show coupling constants through the hydrogen bond, (1h)J((15)N- (1)H) and (2h)J((15)N-(15)N). The position of the tautomeric equilibria, i.e., on what nitrogen atom is the proton, was determined in the solid state and in solution. The crystal structure of N[[5-[(phenylamino)methylene]-1,3-cyclopentadien-1-yl]methylene]pyrrole-1-amine (3) has been determined by X-ray analysis. In solution, both N-H and C-H tautomers were observed and their structures assigned by NMR spectroscopy. Particularly useful is the value of the (1)J((15)N-(1)H) coupling constant.
Sanz
Dionisia
D
Departamento de Química Orgánica y Biología, Facultad de Ciencias, UNED, Senda del Rey 9, Eminus sign28040, Madrid, Spain. dsanz@ccia.uned.es
Pérez-Torralba
Marta
M
Alarcón
Sergio Hugo
SH
Claramunt
Rosa María
RM
Foces-Foces
Concepción
C
Elguero
José
J