Abstract
The title salt [systematic name: 4-(2-methoxyphenyl)piperazin-1-ium 2-carboxy-4,6-dinitrophenolate], C11H17N2O+·C7H3N2O7 -, exhibits secondary nitro-gen atoms (N-H) in the 2-meth-oxy-phenyl-piperazine (2MeOPP) cation, which is protonated with a phenolic hydrogen atom of 3,5-di-nitro-salicylic acid (DNSA). One of the oxygen atoms of the nitro group in the 3,5-di-nitro-salicylate anion is disordered over two orientations with occupancy factors of 0.65 (7) and 0.35 (7) . The 2-meth--oxy-phenyl-piperazinium cation and 3,5-di-nitro-salicylate anion are linked in the asymmetric unit by a bifurcated N-H⋯O hydrogen bond, which formed is between the H atom in the protonated piperazinium unit of the cation and the carb-oxy-lic acid group in the anion. The piperazine ring adopts a chair conformation. The crystal structure features N-H⋯O and C-H⋯O hydrogen bonds inter-actions, which lead to the formation of a sandwich-like arrangement. Hirshfeld surface analysis was used to determine the relative contributions of various inter-molecular inter-actions, indicating that that H⋯O/O⋯H (38. 3%) and H⋯H (31. 8%) contacts are the major contributors.