1-[2-(Carboxy­meth­oxy)phen­yl]-N-(4-chloro­phen­yl)methanimine oxide

In the title resonance conformer, C(15)H(12)ClNO(4), the central C–N bond [1.297 (2) Å] has considerable double-bond character and the N–O bond [1.3215 (18) Å] indicates formal negative charge on the oxygen atom. Considerable deviations from co-planarity are evident in the mol­ecule, with both benzene rings twisted out of the central C–C–N–C plane [the dihedral angle formed between the rings = 81.99 (8)°]. Similarly, the carboxylic acid residue occupies a position almost normal to the plane of the benzene ring to which it is connected [C—C—O—C torsion angle = −78.42 (17)°]. The most prominent inter­molecular inter­actions involve the carboxylic acid the N(+)–O(−) residues with the O—H⋯O hydrogen bonds leading to helical supra­molecular chains along the b axis. These chains are connected into layers via C–H⋯O(carbon­yl) inter­actions and the layers are consolidated into the crystal structure by C–H⋯Cl contacts.