Abstract
The title Schiff base compound, C16H17NO4, crystallizes as a zwitterion, with the phenolic H atom having been transferred to the imino group. The resulting iminium and hy-droxy groups are linked by an intra-molecular N-H⋯O hydrogen bond, enclosing an S(6) ring motif. The conformation about the C=N bond is E and the dihedral angle between the benzene and pyran rings is 70.49 (6)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming a three-dimensional supra-molecular structure. There are also C-H⋯π inter-actions and offset π-π inter-actions, involving the pyran rings [inter-centroid distance = 3.4156 (8) Å], which consolidate the three-dimensional structure. Quantum chemical calculations of the mol-ecule are in good agreement with the solid state keto-amine (NH) form of the title compound.
Highlights
The title Schiff base compound, C16H17NO4, crystallizes as a zwitterion, with the phenolic H atom having been transferred to the imino group
The resulting iminium and hydroxy groups are linked by an intramolecular N—HÁ Á ÁO hydrogen bond, enclosing an S(6) ring motif
It crystallizes in the zwitterionic form, with the phenolic H atom having been transferred to the imino group
Summary
Hydroxy Schiff bases have been studied extensively for their biological, photochromic and thermochromic properties (Garnovskii et al, 1993; Hadjoudis et al, 2004) They can be used as potential materials for optical memory and switch devices (Zhao et al, 2007). Ohydroxy Schiff bases have been observed in the keto form, in the enol form or in an enol/keto mixture (Nazır et al, 2000; Antonov et al, 2000) due to the H-atom transfer. Another form of the Schiff base compounds is their zwitterionic form (Ogawa & Harada, 2003). The molecular structure of the title compound is similar to that of (E)-4hydroxy-3-[N-(4-hydroxyphenyl)ethanimidoyl]-6-methyl-2Hpyran-2-one (Djedouani et al, 2015), which crystallizes as a zwitterion
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call