metal-organic compounds
Open access
The crystal structure of the title compound, [Cu(H2O)6](BF4)2·3C4H4N2O2, comprises discrete [Cu(H2O)6]2+ cations and BF4− anions along with three equivalents of pyrazine 1,4-dioxide (pzdo). The hexaaquacopper(II) ion and all three pzdo molecules lie about crystallographic inversion centers. The lattice is supported by an extensive hydrogen-bonding network. O—HO hydrogen bonding between the [Cu(H2O)6]2+ and pzdo units creates a pseudo-hexagonal lattice parallel to the bc plane. The BF4− anions lie in the voids of that lattice, held in place by O—HF hydrogen bonds, and also generate BF4−–pzdo–BF4−–pzdo stacks via short FN contacts [2.866 (3)–3.283 (4) Å].
organic compounds
Open access
The crystal structure of the title salt, C12H9N2+·HSO4−·H2O, comprises inversion-related pairs of phenazinium ions linked by C—HN hydrogen bonds. The phenazinium N—H atoms are hydrogen bonded to the bisulfate anions. The bisulfate anions and water molecules are linked by O—HO hydrogen-bonding interactions into a structural ladder motif parallel to the a axis.