(Z)-6-{[1,3-dihydroxy-2-(hydroxy-methyl)propan-2-yliminio]methyl} 2-ethoxyphenolate, (Z)-6-{[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yliminio]methyl}-4-nitratocyclohexa-2,4-dienone monohydrate and (R,E)-2-[(1-hydroxybutan-2-ylimino)methyl]phenol

Abstract

The title compounds C13H19NO5, C11H14N2O6 center dot H2O and C11H15NO2, respectively, have been derived from 3-ethoxysalicylaldehyde, 5-nitrosalicylaldehyde and salicylaldehyde, respectively. The C-O and N-C bond distances, and three hydrogen bonds formed by the phenolate O atom, show that the zwitterionic form exists in the first compound. The second compound is transformed to the quinoid form as a result of resonance between the zwitterionic form and the nitro group. The third compound exists in the phenol-imine form, with appropriate C-N and C-O bond distances.