SYNTHESIS AND STRUCTURE OF CYCLIC SELENIUM OXIDE SEVISE2IVO7

Nitromethane is the only presently known organic solvent for highly re active selenium trioxide (SeO3)(4). The stability of the solutions is limited and the beginning of the reaction between both components depe nds significantly on concentration and temperature. The nitromethane s olvate of cyclic triselenium heptoxide Se3O7 . CH3NO2 is the major sol id product at the temperature 20-30 degrees C and concentration range 3-20% SeO3. Crystal and molecular structure of this compound was deter mined by X-ray structure analysis and vibrational spectroscopy. The so lvating molecule CH3NO2 is removable from SE(3)O(7) . CH3NO2 in vacuo. If reaction temperature does not exceed 10 degrees C, selenium pentox ide (Se2O5)(n) is formed instead of SE(3)O(7) . CH3NO2. Dinitrosyl tri selenate (NO)(2)Se3O10, nitrosyl hydrogendiselenate NOHSe2O7, nitrosyl hydrogenselenate NOHSeO4, nitrosyl hydrogenselenatoselenite NOHSe2O6 and selenium dioxide (SeO2)(n) were further identified in the solid re action products. The selenic and/or oligoselenic acids remains in the nitromethane solution. CO2 and N2O3 were found as gaseous products.