Crystal structure of 3,14-diethyl-2,6,13,17-tetraazoniatricyclo[16.4.0.0 7,12 ]docosane tetrachloride tetrahydrate from synchrotron X-ray data

The crystal structure of the hydrated title salt, C 22 H 48 N 4 4+ ·4Cl − ·4H 2 O (C 22 H 48 N 4 = H 4 L = 3,14-diethyl-2,6,13,17-tetraazoniatricyclo[16.4.0.0 7,12 ]docosane), has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit comprises one half of the macrocyclic cation (completed by crystallographic inversion symmetry), two chloride anions and two water molecules. The macrocyclic ring of the tetracation adopts an exodentate (3,4,3,4)- D conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the macrocycle N—H groups and water O—H groups as donors, and the O atoms of the water molecules and chloride anions as acceptors, giving rise to a three-dimensional network.