MAGNETIC CIRCULAR DICHR0ISM OF MATRIX ISOLATED GROUP IVb DIATOMIC METAL OXIDES

Abstract

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 $TiO_{2}$ at $\sim 2300^{\circ} K$ and trapped in argon at $14^{\circ} $K. The absorption spectrum was similar to that of $Weltner^{1}$ - 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 $^{3}\Delta_{r}$(zero C term). The absence of MCD for the $\alpha$ transition also confirms its assignment as $^{3}\Delta 1\leftarrow\ ^{3}\Delta 1$ (A term is predicted zero). The spectra of zirconium oxide and hafnium oxide will also be discussed.