Crystals of the Kemp’s triacid salts – Part VI: Supramolecular architecture in the crystal of Kemp’s triacid with tris(2-aminoethyl)amine

A complex crystal [H3KTA–TAEA–EA] is composed of triply deprotonated Kemp’s triacid molecule (KTA3−), triply protonated tris(2-aminoethyl)amine (H3TAEA3+) molecule and one ethanol molecule (EA) as a solvate. The ring of the (KTA3−) trianion exhibits an uncommon twisted boat conformation with two carboxylic groups in the axial positions and one in the equatorial position. In the crystal each KTA3− trianion is hydrogen-bonded with four H3TAEA3+ molecules forming three-dimensional hydrogen-bonded network within the supramolecular complex. The ethanol molecules form a uncommon dimer bonded by very weak tandem hydrogen bonds. The IR spectrum of the crystal is consistent with the results obtained by the X-ray study and provides spectroscopic evidence for the crystal formation.