ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Cobalt(II) selenites

M. Ebert, Z. Mička, and I. Peková

Department of Inorganic Chemistry, Faculty of Natural Sciences, Charles University, 128 40 Prague

Abstract:  The solubility diagram of CoSeO₃ —SeO₂ —H₂O at 298 К was studied for the first time; on the basis of this diagram, the dihydrate of cobalt(II) hydrogenselenite, Co(HSeO₃)₂ . 2H₂O, was prepared. The CoSeO, 2H₂O and Co(HSeO₃)₂ -2H₂O selenites were studied by the powder X-ray technique and by infrared molecular and electronic reflectance spectroscopy and their mag­ netic properties were determined. The force constants of the bonds between selenium and oxygen were found from the infrared spectra: 454 N m^-1 for CoSeO, 2H₂O, 541 N m^-1 in the SeO, group, and 307 N m^-1   in the SeOH group for Co(HSeO₃)₂ . 2H₂O. Weak to strong hydrogen bonds between the water molecules and the anions, between water molecules, and between anions are present in both selenites. Study of the electronic reflectance spectra and of the magnetic properties indicated octahedral arrangement of the coordination sphere of the cobalt(II) cation, yielding a weak crystal field with a high-spin arrangement.

Full paper in Portable Document Format: 362a169.pdf

Chemical Papers 36 (2) 169–177 (1982)