Bis[2-(2,4-dinitrobenzyl)pyridinium] biphenyl-4,4′-disulfonate trihydrate

Abstract

In the structure of the title salt, 2C12H10N3O4 +·C12H8O6S2 2−·3H2O, determined at 173 K, the biphenyl-4,4′-disulfonate dianions lie across crystallographic inversion centres with the sulfonate groups inter­acting head-to-head through centrosymmetric cyclic bis­(water)-bridged hydrogen-bonding associations [graph set R 4 4(11)], forming chains. The 2-(2,4-dinitro­benz­yl)pyridinium cations are linked to these chains through pyridinium–water N—H⋯O hydrogen bonds and a two-dimensional network is formed through water bridges between sulfonate and 2-nitro O atoms, while the structure also has weak cation–anion π–π aromatic ring inter­actions [minimum ring centroid separation = 3.8441 (13) Å].