Crystal and molecular structure of potassium 2-amino-6-sulfinato-purine monohydrate

The crystal and molecular structure of the title compound, K[C₅H₄N₅O₂S]H₂O, has been determined at room temperature. The structure determination reveals that the negative charge on the anion is localised on the sulfinate group which results in significant rearrangement of -electron density within the purine ring. The K⁺ cation exists in a N₃O₄ donor set which defines a distorted trigonal prismatic geometry. Crystals of K[C₅H₄N₅O₂S]H₂O are triclinic with space group and unit cell dimensionsa=8.248(2),b=8.710(2),c=6.988(6) Å, =99.87(4), =102.84(5), and =78.35(2)°,Z=2.