Novel gaseous polyatomic binary and ternary lanthanide oxides
Abstract
A variety of novel gaseous polyatomic binary and ternary oxides were observed at ambient temperature arising from lanthanide (Ln) nitrate Schiff base complexes, simple salts and sesquioxides, in an FAB mass spectrometer. The new binary oxides (as singly positive ions) detected are Ln2O3, Ln3O3, Ln3O4, Ln4O4, Ln4O5, Ln4O6, Ln5O6, Ln5O7, Ln5O8, Ln6O8, Ln6O9, Ln7O10, Ln8O11, Ln8O12 and Ln9O13; the ternary gaseous oxides are CeEuO2, CeEu2O3 and Ce2EuO4, LaYbO2, La2YbO4 and LaYb2O4; NdHoO3, Nd2HoO4, and NdHo2O4; YTmO3; YxTm3-xO4, x=1-2; YxTm4-xO6, x=1-3; YxTm5-xO7, x=1-4; YxTm6-xO9, x=1-5. Some of these oxides show the lanthanide cations in unusual oxidation states. Gadolinium-gallium ternary oxides, GdGaO2, GdGaO3 and Gd2GaO4 were also detected. The FAB MS environment is significantly reducing, yielding a homologous series EunOn where Eu2+ is dominant (E°(Eu3+/Eu2+)=-0.35 V) and no gallium or indium oxides (E°(M3+/M°=-0.34 V (In), -0.53 V (Ga)) were formed. The stoichiometry of the polylanthanide ternary oxides formed is determined largely by the chemistry of the major metallic component. The gaseous polyatomic oxides are probably formed through a reductive condensation process involving primary species Ln+ and LnO+ formed when the rare earth compounds are struck by fast Xe atoms. The demonstrated possibility of double component oxide formation broadens the number and types of gaseous lanthanide oxides which are accessible. © 1988.