1-[((E)-{2-[(2-Nitro-benz-yl)(2-{[(E)-(2-oxidonaphthalen-1-yl)methyl-idene]aza-nium-yl}eth-yl)amino]-eth-yl}aza-niumyl-idene)meth-yl]naphthalen-2-olate monohydrate.

The title Schiff base compound, C(33)H(30)N(4)O(4)·H(2)O, adopts an E configuration with respect to each C=N double bond. In the mol-ecule, there are naphthoxide anions and the protonated imino N atoms. Intra-molecular N-H⋯O hydrogen bonds lead to the formation of approximately planar (maximum deviation 0.029 Å for H atom) six-membered rings.. In the crystal, mol-ecules are linked by O-H⋯O and N-H⋯O hydrogen bonds as well as C-H⋯O contacts, leading to the formation of a three-dimensional network.