Characterization of Dicarboxylic Salts of Protonated Triethylenetetramine Useful for the Treatment of Copper-Related Pathologies.

X-ray crystal structures of three salts of protonated triethylenetetramine, (H4TETA)4, with succinate, maleate, and fumarate anions are reported. Structures of the complexes (H4-triethylenetetramine)(hydrogenmaleate)4·2H2O (H4TETA)(Hmal)4·2H2O (1), (H4-triethylenetetramine)(hydrogenfumarate)4·3.3H2O (H4TETA)(Hfum)4·3.3H2O (2), and (H4-triethylenetetramine)(succinate)2(H4TETA)(suc)2(3) all form assemblies of alternating two-dimensional layers of (H4TETA)4and the anionic species via hydrogen-bond networks. Both classical and nonclassical hydrogen bonds between the protonated amine groups, anions, and water molecules were observed. X-ray powder diffraction measurements, differential thermal analysis/thermogravimetry, density vapor sorption, and Karl Fischer titration measurements were performed to obtain confirmatory information about the water content in the structures 1and 2and to examine polymorphism within the salts. The nonhydrated salt 3was determined to be the most favorable salt formulation for use in medicinal applications. [ABSTRACT FROM AUTHOR]