Knowledge Bank

An apparatus for the measurement of magnetic circular dichroism (MCD) and UV-visible absorption spectra of matrix-isolated high temperature species has been constructed. The spectra of Group IVb diatomic oxides have been examined. TiO was prepared by vaporization of $TiO2$ at $\sim 2300\circ K$ and trapped in argon at $14^{\circ} $K. The absorption spectrum was similar to that of $Weltner1$ - the $\gamma ,\gamma \prime$ and $\alpha$ systems were observed. The MCD spectra showed no temperature dependence in the range of 14 to $24\circ K$ which confirms the assignment of the ground state as $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Delta r$(zero C term). The absence of MCD for the $\alpha$ transition also confirms its assignment as $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Delta 1\leftarrow 3\Delta 1$ (A term is predicted zero). The spectra of zirconium oxide and hafnium oxide will also be discussed.