Crystal Structure and Conformation of 2-{(2′-Aminobenzyl)iminoethyl}- 5-methoxyphenol

Abstract

Abstract The Schiff base, 2-{(2′-aminobenzyl)iminoethyl}-5-methoxyphenol, 1,2 -C6H4[NH2-2 ʹ]-CH2N=CHC6H3(OMe-5)OH (I), has been prepared by the reaction of 2 -amino-1-benzylamine and 2-hydroxy-4-methoxyacetophenone in methanol. The molecular structure has been con­firmed by single crystal X-ray crystallography (triclinic, space group P 1̄, a = 7.201(2), b = 9.802(2), c = 9.993(2) Å, α = 83.09(2), β = 73.49(2), γ = 84.09(2)°, R = 0.0415 for 2611 independent reflections). The 1H and 13C NMR spectra in CDCI3 solution indicate the forma­tion of some other minor conformations or dissociation in solution. The title compoundois not planar. Intramolecular hydrogen bonding occurs between O(1) and N(1) atoms [2.528(2) Å], the hydrogen atom essentially being bonded to the nitrogen atom. Minimum energy conformations from AMI were calculated as a function of four torsion angles. The optimized geometry of the molecular structure corresponding to the non-planar conformation is the most stable conformation in all calculations. The results strongly indicate that the minimum energy conformation is primarily determined by non-bonded hydrogen-hydrogen repulsions.