5-nitrosalicylic acid and its proton-transfer compounds with aliphatic Lewis bases

Abstract

The crystal structures of the proton-transfer compounds of 5-nitrosalicylic acid (5-nsa) with morpholine (morph), hexamethylenetetraminc (hmt), and ethylenediamine (en) have been determined and their solid-state packing structures described. The compounds are [(morph)+(5-nsa) -] 1, [(hmt)+(5-nsa)-·H2O] 2, and [(en)2+(5-nsa)-·H2O] 3. In all compounds, protonation of the hetero-nitrogen of the Lewis base occurs. With 1, the 5-nsa anions and the morpholine cations lie, respectively, in or across crystallographic mirror planes and are linked within the planes by hydrogen-bonding interactions through the aminium group and the carboxylic and phenolic oxygens of the anionic 5-nsa species giving a t..