1-{[(E)-(4-{[(2Z)-2,3-Di­hydro-1,3-thia­zol-2-yl­idene]sulfamo­yl}phen­yl)iminium­yl]meth­yl}naphthalen-2-olate

In the title zwitterionic compound, C(20)H(15)N(3)O(3)S(2), the 2-hy­droxy­naphthalene-1-carbaldehyde group A, the anilinic unit B and the 1,3-thia­zol-2(3H)-imine group C are each approximately planar with r.m.s. deviation of 0.0721, 0.0412 and 0.0125 Å, respectively. The dihedral angles between A/B, A/C and B/C are 24.70 (10), 79.97 (7) and 83.14 (6)°, respectively. There is an intra­molecular S(6) motif involving the imine N—H and the naphtho­late O atom. In the crystal, inversion-related mol­ecules form dimers as a result of N—H⋯N and N—H⋯O hydrogen bonds with R (2) (2)(8) and R (1) (2)(4) motifs, respectively. Weak π–π inter­actions between the benzene and naphthyl rings of inversion-related mol­ecules have ring centroid–centroid distances of 3.638 (2) and 4.041 (2) Å. A C—H⋯π inter­action occurs between the thia­zol ring and the benzene ring of an adjacent mol­ecule.