The title compound, C6H13N2+·C20H7Br4O5-, is a molecular salt of singly protonated 1,4-diazabicyclo[2.2.2]octane and the eosinide monoanion. Contrary to a handful of previous crystal structures which contain eosin in its dianionic form, here, the carboxyl group of the anion has retained its H atom. The dihedral angle between the triple ring system and the pendant benzene ring in the anion is 86.0 (2)°. In the crystal structure, the components interact by way of a bifurcated N-H center dot center dot center dot (O,Br) hydrogen bond linking cation and anion, and an O-H center dot center dot center dot O hydrogen bond which links the anions into infinite chains propagating in .
|Number of pages||12|
|Journal||Acta Crystallographica Section E: Structure Reports Online|
|Publication status||Published - Sep 2007|