Two salts of di-p-toluoyltartaric acid with aromatic amines.

The structures of bis[(R)-(+)-1-phenylethylammonium] (2R,3R)-(-)-2,3-di-p-toluoyloxybutanedioate methanol disolvate monohydrate, 2C8H12N(+).C20H16O8(2-).2CH4O.H2O, (I), and bis(benzylammonium) (2R,3R)-(-)-2,3-di-p-toluoyloxybutanedioate dihydrate, 2C7H10N+.C20H16O8(2-).2H2O, (II), exhibit extensive hydrogen bonding, with (N-)H...O and (O-)H...O distances in the ranges 2.716 (2)-2.929 (3) and 2.687 (2)-2.767 (2) angstroms, respectively, in (I), and 2.673 (2)-2.888 (2) and 2.785 (2)-2.931 (2) angstroms, respectively, in (II). The amine groups are protonated and the carboxylate groups of the tartrate anions are fully deprotonated. The conformation of the toluoyltartrate anion and its molecular parameters are similar in both structures.