Anhydrous quinolinium dihydrogen citrate

Abstract

In the title compound, C9H8N+烶H7O7-, the dihydrogen citrate anions form a convoluted two-dimensional hydrogen-bonded substructure through head-to-tail interactions with the interstitial p-stacked quinolinium cations linked to it peripherally through cyclic R12(5) N+-H...O(carboxyl/hydroxyl) hydrogen-bond interactions. The loss of a proton from one of the ߭carboxylic acid groups of the citric acid generates a chiral centre in the anion, but these form a racemate in the centrosymmetric crystal structure.