The 1 : 1 adduct of Kemp's triacid with 2-aminopyridine

The crystal structure determination of the molecular proton-transfer adduct of Kemp's triacid (cis-cis-1,3,5-trimethylcyclohexane-1,3,5-tricarboxylic acid, KTA) with 2-aminopyridine (2-APY), namely 2-aminopyridinium 3,5-dicar boxy-1,3,5-trimethylcyclohexanecarboxylate, 2-APY(+).KTA(-) or C5H7N2+.C-12 H17O6-, has revealed a centrosymmetric hydrogen-bonded cyclic KTA homodime r repeating unit [O . . .O 2.524 (4) Angstrom] linked into a polymer struct ure through the pyridinium and amino groups of the 2-APY molecule [O . . .N 2.736 (4), 2.989 (4) and 2.999 (4) Angstrom].