NEW ALKALI-METAL ORTHONITRATES AND THEIR CHARACTERIZATION BY VIBRATIONAL SPECTROSCOPY

For the first time the alkali metal orthonitrates Rb3NO4, Cs3NO4, AA2'NO4 (A,A' = Na, K, Rb), A3A3'(NO4)2 (A = K, Rb, Cs; A' = Na, K, Rb except Cs3Na3(NO4)2) and AA5'(NO4)2 (A,A' = Na, K) have been prepared by solid state reactions of alkali metal oxides with alkali metal nitrates. All new compounds were proved to contain NO43--groups by vibrational spectroscopy. The wavenumbers of the fundamental vibrations are strongly depending on the radius of the cations in an unexpected amount.