Figure 2
Part of the crystal structure of (I) , showing the piperazine-1,4-diium cation linked to four neighboring anions via N1—H1A⋯O1, N1—H1B⋯O2, C9—H9A⋯O2, and C9—H9A⋯Br1 hydrogen bonds, forming a molecular double layer parallel to the bc plane. Symmetry codes as in Table 1. |