Preparation, crystal structure and IR spectra of BeSeO3 center dot H2O - Hydrogen bonds and correlation of IR and structure data in the monohydrates MSeO3 center dot H2O (M = Be, Ca, Mn, Co, Ni, Zn, Cd)

BeSeO3 . H2O (oP32) has been obtained by treating amorphous BeSeO3 . 4H(2)O precipitated from Be(HSeO3)(2) solutions hydrothermally at 150 degrees C. The crystal structure (P2(1)2(1)2(1), a = 560.59(4), b = 755.25(5), c= 781. 14(5)pm, Z=4, D-X=3.092 gcm(-3), R=0.018 for the 2034 reflections with I > 2 sigma(I) of the enantiomer investigated) contains BeO3(H2O) tetrahedra bu ilt up from three selenite and one water oxygen atoms. The BeO3(H2O) tetrah edra are 3 D-connected via Se atoms of trigonal pyramidal SeO32- ions. The Be-O distances are 161.8 to 164.4 pm. The Se-O bond lenghts (169.2-170.3 pm ) and the O-Se-O bond angles (98.1-101.4 degrees) are normal. The water mol ecules of crystallization form together with the SeO32- ions screw-like hyd rogen bond systems along [100]. Despite the strong synergetic effect of the Be2+ ions, the hydrogen bonds (d(OH ... O)= 267.4 and 276.4pm, respectivel y; upsilon(OD) of matrix isolated HDO molecules: 2244 and 2405 cm(-1), resp ectively) are normal compared to other neutral selenite hydrates. Together with the hitherto known monohydrates (MSeO3)-Se-II . H2O and other berylliu m salt hydrates, the hydrogen bonds of BeSeO3 . H2O are discussed with rega rd to their geometry and IR spectroscopy.