Knowledge Bank

The matrix isolation technique has been applied to the reaction of alkaline earth metals, Ca, Sr and Ba, with molecular oxygen and ozone. In addition to the azonide ion, the metal oxides and superoxides have been isolated, and their frequencies determined. The frequencies for BaO SrO, and CaO in nitrogen matrices are, respectively, 613, 620, and $707cm-1$, while the frequencies of the interionic mode of the superoxides $BaO2$, $SrO2$ and $CaO2$ were, respectively, 541, 480 and $497cm-1$. The pattern of matrix shifts from the gas phase indicates that the ground state of CaO is singlet sigma. We have also observed that a nitrogen matrix stabilizes ionic species much more efficiently than argon matrices, and accordingly, oxygen atom abstraction from ozone occurs much more rapidly in nitrogen matrices.