Crystal structure and theoretical studies of the keto-enol isomerism of N,N'-bis(salicylidene)-o-phenylenediamine (salophen).
The Schiff base N,N'-bis(salicylidene)-o-phenylenediamine (salophen) was prepared by the condensation of salicylaldehyde with o-phenylenediamine in ethanol solution. The compound was characterized by elemental analysis, infrared (IR), (1)H, (13)C and (1)H(15)N HMBC nuclear magnetic resonance (NMR) spectroscopic measurements, and also by X-ray diffraction. The tautomerism of salophen was also studied by calculations using density functional theory (DFT). Two of the three tautomers were shown to coexist. A comparison of the DFT data of the three tautomers has shown that the most stable one is salophen 1, which is in accordance with experimental X-ray crystallographic data.
Chemistry Department, Exact Sciences Institute, 36036-330 Juiz de Fora, MG, Brazil.
Vinicius Z
VZ
Mota
Gustavo S G
GS
de Carvalho
Pedro P
PP
Corbi
Fernando R G
FR
Bergamini
André L B
AL
Formiga
Renata
R
Diniz
Maria C R
MC
Freitas
Adilson D
AD
da Silva
Alexandre
A
Cuin
D000447:Aldehydes / Q000737:chemistry; D018360:Crystallography, X-Ray; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D011789:Quantum Theory; D012459:Salicylates / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
D000447:Aldehydes; D012459:Salicylates; D012545:Schiff Bases; C090416:salophen; C013243:salicylaldehyde