Crystal structure studies of 4-ethyl­piperazin-1-ium 3,5-di­nitro­benzoate, 4-methyl­piperazin-1-ium 3,5-di­nitro­benzoate and 4-methyl­piperazin-1-ium 4-iodo­benzoate

As part of our ongoing investigation on the chemical and biological properties of piperazinium salts, we synthesized three novel compounds: 1-ethyl­piperazinium 3,5-di­nitro­benzoate (I), 1-methyl­piperazinium 3,5-di­nitro­benzoate (II) and 1-methyl­piperazinium 4-iodo­benzoate (III). The crystal structures of these compounds are built up of organic layers formed by the strong connection between the mol­ecules by hydrogen bonds of type N—H⋯O. These layers are linked through N—H⋯O hydrogen bonds and C—H⋯O inter­actions or C—I⋯N halogen bonding, leading to the formation of a three-dimensional network.