Lithium dipotassium citrate monohydrate, LiK2C6H5O7(H2O)

Abstract

The crystal structure of dilithium potassium citrate monohydrate, Li+·2K+·C6H5O7 3−·H2O or LiK2C6H5O7·H2O, has been solved by direct methods and refined against laboratory X-ray powder diffraction data, and optimized using density functional techniques. The complete citrate trianion is generated by a crystallographic mirror plane, with two C and three O atoms lying on the reflecting plane, and chelates to three different K cations. The KO8 and LiO4 coordination polyhedra share edges and corners to form layers lying parallel to the ac plane. An intramolecular O—H...O hydrogen bond occurs between the hydroxyl group and the central carboxylate group of the citrate anion as well as a charge-assisted intermolecular O—H...O link between the water molecule and the terminal carboxylate group. There is also a weak C—H...O hydrogen bond.