Guanidinium 4-hydroxy­pyridinium-2,6-dicarboxyl­ate

The crystal structure of the title compound, CH₆N·C₇H₄NO₅^-, shows that both intra- and intermolecular proton transfers have occurred. Hydrogen-bonding interactions, in addition to ion-pairing forces, are observed between the cation and anion.

Dichloro­bis(1,10-phenanthroline)mercury(II)

The title compound, [HgCl₂(C₁₂H₈N₂)₂], is a six-coordinate complex with a distorted octa­hedral geometry around the Hg atom. There are some π–π stacking inter­actions in the crystal structure, with short distances between parallel aromatic rings.