A mononuclear Zn(II) complex of (Zn(H₂L) (CH₃OH) Cl₂) (1) has been synthesized by using a nonlinear optically active Zwitterionic Schiff base which is 4-((2-hydroxy-3-methoxybenzylidene) amino) benzoic acid (H₂L). Complex 1 has been structurally analyzed by FTIR and UV spectroscopy, TGA, Powder-XRD and single crystal X-ray diffraction. X-Ray crystallographic studies revealed Zn(II) complex crystallizes in a P21/c space group and exists in a distorted trigonal bipyramidal geometry (τ = 0.68). The topological analysis of complex 1 showed that the underlying net is characterized by an unknown topological type and point symbol {3⁴².4⁶⁸.5¹⁰}, and multilevel analysis of complex packing as dimer gives a 18-c uninodal net with unknown topological type and point symbol {3⁴⁸.4⁹⁹.5⁶}. The calculation results of a Hirshfeld surface analysis have been investigated to explore the H-bonding within the crystal. Third-order non-linear properties were also studied, which revealed that the lower input power (5.0 mM) for the material shows full transparency; however, it becomes opaque for higher input power. Such limiting behavior of complex 1 suggests its potential for instrumental protective devices against high laser illuminations.