Hydrogenium-bis-hydrogensulfate anions adjacent to [S2O7]2− in Rb3[S2O7][H(HSO4)2]: a structural evidence of the increasing acidity of polysulfuric acids with growing chain length

Abstract

Abstract Rb3[H(HSO4)2][S2O7] (monoclinic, C2/c (no. 15), a=1638.75(6), b=768.52(3), c=1187.88(4) pm, β=106.805(2)°, V=1432.14(9)·106 pm, Z=4) was obtained from the reaction of Rb2[CO3] (99.9%, not dried, 150 mg, 0.6 mmol) with neat SO3 in a torch-sealed glass ampoule. The remaining quantity of water in the starting material was obviously sufficient to lead to an H-containing substance. The structure shows the unprotonated disulfate anion [S2O7]2− adjacent to the hydrogenium-bis-hydrogensulfate anion [H(HSO4)2]− with the central hydrogen atom located close to a center of inversion.