1-[4-(Diamino­methyl­eneamino­sulfon­yl)phenyl­iminiometh­yl]-2-naphtholate N,N-dimethyl­formamide disolvate

The asymmetric unit the title compound, C(18)H(16)N(4)O(3)S·2C(3)H(7)NO, contains a mol­ecule in a zwitterionic form with a deprotonated hydroxyl group and an iminium group, and two dimethyl­formamide solvent mol­ecules. The dihedral angles of the guanidine group and the naphthyl ring system with respect to the central benzene ring are 76.04 (7) and 3.45 (9)°, respectively. The conformation of the mol­ecule may be influenced, in part, by two intra­molecular hydrogen bonds, while in the crystal structure, inter­molecular hydrogen bonds form one-dimensional chains along [010].