Structure of dipotassium hydrogen citrate

Dipotassium hydrogen 2-hydroxy-1,2,3-propanetricarboxylate is shown by this crystal structure determination to be ionized at the central carboxyl group and one terminal carboxyl group. Each citrate ion forms an intramolecular hydrogen bond as well as an intermolecular hydrogen bond connecting it to an adjacent citrate ion. Each K ion is surrounded by eight O atoms from several citrate ions. The metal-oxygen distances range from 2.706 to 3.136 A.