Adeninium cytosinium sulfate

In the title compound, C5H6N5+·C4H6N3O+·SO42−, the adeninium (AdH+) and cytosinium (CytH+) cations and sulfate dianion are involved in a three-dimensional hydrogen-bonding network with four different modes, viz. AdH+...AdH+, AdH+...CytH+, AdH+...SO42− and CytH+...SO42−. The adeninium cations form N—H...N dimers through the Hoogsteen faces, generating a characteristic R22(10) motif. This AdH+...AdH+ hydrogen bond in combination with AdH+...CytH+ H-bonds leads to two-dimensional cationic ribbons parallel to the a axis. The sulfate anions interlink the ribbons into a three-dimensional hydrogen-bonding network and thus reinforce the crystal structure.