RbH2AsO4

Abstract

RbH2AsO4, rubidium dihydrogenarsenate (RDA), was synthesized by partial neutralization of an aqueous H3AsO4 solution with aqueous Rb2CO3. Its paraelectric room-temperature phase is composed of virtually regular tetrahedral [AsO2(OH)2]− anions and Rb+ cations, both located on -4 positions. The [AsO2(OH)2] units are connected via O—H...O hydrogen bonds into a three-dimensional network, whereby the H atoms are equally disordered between the O atoms. The Rb+ cations are located in channels running along the directions and coordinated by eight O atoms located at the vertices of a snub disphenoid.