Three Crystal Structures of Terephthalic Acid Salts of Simple Amines

Abstract

Diphenethylamine forms two adducts (1 : 1, la and 2 : 1, 1b) with terephthalic acid (H(2)TPA). The former is bis(diphenethylammonium)H-2 TPA center dot TPA(2-) and the latter is bis(diphenethylammonium)center dot TPA(2-). The amine cis-2,6-dimethylpiperidine forms a hydrated 2 : 1 adduct, bis(2,6-dimethylpiperidinium)center dot TPA(2-)center dot H2O (2). The crystal structures of all three compounds were determined. All H(2)TPA and TPA(2-) residues display inversion symmetry, while the water oxygen atom of 2 lies on a twofold axis. Packing analyses have identified some supramolecular synthons known from related structures.