Ozone forms compounds with the alkali and alkaline earth metals. These compounds contain the trioxide (1-), O3-. As we would expect from the
lattice stability arguments, it is the larger cations, such as cesium, that form the most stable trioxides. It has been shown that the trioxide (1-)
is also V-shaped, so the molecular orbital diagram should be similar to trioxygen itself. Thus, the additional electron in the anion should enter the
pi anti-bonding orbital. This arrangement would reduce the pi bonding to one-half, or one-fourth, per oxygen-oxygen bond. Experimental measurments
have shown this to be the case. The oxygen-oxygen bond length is 135 pm in the trioxide (-1) ion, slighlty longer then the 128 pm bond in trioxygen
itself. |