(z)-6 -2 (z)-6 Methyl}-4 Monohydrate and (r,e)-2 2-Ylimino)

Abstract

The title compounds C<inf>13</inf>H<inf>19</inf>NO<inf>5</inf>, C <inf>11</inf>H<inf>14</inf>N<inf>2</inf>O<inf>6</inf>·H<inf>2</inf>O and C<inf>11</inf>H<inf>15</inf>NO<inf>2</inf>, respectively, have been derived from 3-ethoxy-salicylaldehyde, 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. © 2006 International Union of Crystallography.