Structure of trirubidium hydrogenbis(sulfate), Rb3H(SO4)2

Msub(r)=449.5, monoclinic, C2/c, a=15.144 (3), b=5.890 (3), c=10.149 (1) A, β=102.55 (1)0, V=883.7 A3, Z=4, Dsub(x)=3.380 Mg m-3, Mo Kα, lambda=0.71073 A, μ=16.58 mm-1, F(000)=832, T=292 K, final R=0.048 for 1006 observed reflections. Trirubidium hydrogenbis(sulfate) is isostructural with its triammonium analogue. The room-temperature structure for these two salts is pseudohexagonal and phase transitions to hexagonal symmetry at elevated temperatures are predicted to involve changes in the O-H-O hydrogen bonds. (orig.)