Direct synthesis of bis( n-alkylammonium) monohydrogen phosphates by solid–vapour reaction

Abstract

n-Alkylamines ( C n H 2n+1 NH 2, n=2–6) have been intercalated into orthophosphoric acid by exposing the solid to the vapour of the amines. Compounds were obtained of both the (C n H 2 n+1 NH 3)(H 2PO 4) and (C n H 2 n+1 NH 3) 2(HPO 4)·H 2O formulae. In the novel monohydrogen phosphates, n-alkylamines form a bimolecular film inclined an average of 42.6° with respect to the phosphate layer plane. These compounds are proposed as starting materials for the hydrothermal synthesis of new open-framework metal phosphates.