SYNTHESIS AND CRYSTAL-STRUCTURE OF CESIUM DIHYDROGEN DIPHOSPHATE

Cesium dihydrogen disphosphate has been prepared through a metathesis reaction using Ag2H2P2O7 as starting material. Cs2H2P2O7 is monoclinic, C2/c, with Z = 4 and the following unit-cell dimensions: a = 7.977(3), b = 9.064(6), c = 11.406(6) angstrom, beta = 90.29(2)-degrees. Crystal structure determination has been performed by using 1,790 reflections with a final R value of 0.034. As previously observed in all atomic arrangements of acidic diphosphates, the anions interconnected by strong hydrogen bonds assemble themselves such that an infinite network is formed. In the title compound, one observes the formation of layers of [H2P2O7]2- entities, perpendicular to the c direction, alternating with planes of cesium atoms. The phosphoric group has a twofold internal symmetry.