Preparation, crystal structure and infrared spectroscopy of the new compound rubidium beryllium sulfate dihydrate, Rb2Be(SO4)2·2H2O

The strengths of the hydrogen bonds in the title compound as deduced from the infrared wavenumbers of the uncoupled OD stretches of matrix-isolated HDO molecules (isotopically dilute sample) are discussed in terms of the Ow⋯O hydrogen bond distances, the different hydrogen bond acceptor capabilities of the sulfate oxygen atoms and the strong BeOH2 interactions (synergetic effect). The intramolecular OH bond lengths are derived from the νOD versus rOH correlation curve [H.D. Lutz, C. Jung, J. Mol. Struct. 404 (1997) 63].