Molecular interactions in the anomalous salt: 2-Aminopyridinium maleate maleic acid

A new anomalous salt in 2:3 ratio of 2-aminopyridine and maleic acid was obtained. This salt, 2-aminopyridinium maleate maleic acid crystalllizes in monoclinic C2/ c space group. 2-Aminopyridinium maleate maleic acid is isostructural to 2-amino 3-methyl pyridiniminium maleate maleic acid and is the third complex crystallized from 2-aminopyridine and maleic acid in aqueous solution in a different stochiometric ratio. This salt is stabilized by N H…O and O H…O bydrogen bonds apart from π– π interactions.