Crystal Structure of a Novel Proton-Transfer Compound: Ethylenediguanidinium Pyridine-2,6-dicarboxylate Trihydrate

A proton-transfer compound, (EDGH2)(pydc)·3H2O, was synthesized from the reaction of 2,6-pyridinedicarboxylic acid, pydcH2, and ethylenediguanidine, EDG. The crystal structure was determined by single-crystal X-ray diffraction. This compound crystallized in the space group P1 of the triclinic system and contained two molecules per unit-cell. The unitcell parameters were: a = 7.798(1)Å, b = 10.806(2)Å, c = 10.829(2)Å, with α = 102.462(2)°, β = 104.433(2)°, and γ = 96.094(2)°. The final R value was 0.0573 for 3484 measured reflections.