1-{2-[4-(4-Nitrophenyl)piperazin-1-yl]ethyl}-4-aza-1-azoniabicyclo[2.2.2]octane iodide

Abstract

The title compound, C18H28N5O2+·I−, was observed as a main product in an intended 1:1 reaction between 4-iodonitrobenzene and 1,4-diazabicyclo[2.2.2]octane (DABCO). In the reaction, DABCO undergoes a ring opening to yield a quaternary salt of DABCO and 1-ethyl-4-(4-nitrophenyl)piperazine with an iodide anion. The crystal structure determination was carried out as no crystal structure had been previously reported in the investigations describing the corresponding reaction with 4-chloronitrobenze. Indeed, the crystal structure of the title compound confirms the molecular composition proposed earlier for the analogous chloride salt. The cation conformation is similar to the previously reported dinitro analogue 1-{2-[4-(2,4-dinitrophenyl)piperazin-1-yl]ethyl}-4-aza-1-azoniabicyclo[2.2.2]octane chloride [Clegg et al. (2004). Acta Cryst. E60, o291–o293]. The crystal packing is dominated by cation...I− interactions in addition to weak intermolecular C—H...O2N and C—H...N interactions between the cations.