The crystal and molecular structures of 1:1 complexes of dodecyltrimethylammonium bromide and chloride adducts of rac-1,1'-Bi-2-naphthol (hereafter, 12TAB/BNP and 12TAC/BNP) have been determined by X-ray diffraction techniques. The crystal data and crystal structures revealed that the complexes crystallize in monoclinic crystal system with space group (P21/a) and Z-value (4), and also exhibit isomorphous packing structure. The crystal complexes are stabilized by electrostatic interactions, hydrogen bonds, and C-H interactions. The different lattice parameters as well as the different sizes of the halide ions (Br- and Cl-) do not prevent both complexes (12TAB/BNP and 12TAC/BNP) from crystallizing with similar packing as well as common hydrogen bonding network and non-bonded interactions. Thus, the entering or leaving groups (Br-/Cl-) do not alter the existing hydrogen bonding and any other non-bonded interactions and thereby effects isomorphous packing structure.