Knowledge Bank

A high-temperature furnace is being used to perform quantitative absorption spectroscopy on the $A\leftarrow X$ bands of CIO, BrO, and IO, Initial work with an $I2-O2$ mixture at $\sim$ $1000\circ C$ readily showed the 445 nm (2,0) band of 10 in absorption. Since the bond strength of IO is not well known, absorption strength measurements at several different temperatures will be needed to define both bond strength and transition probability. Assuming a value of $\Delta Hfo(IO)=42$ kcal/mole, an approximate value of $fv=0.001$ was obtained for the (2,0) bond. An experimental complication is the fact that the $A\leftarrow X$ transition of each oxide lies in the region of strong continuous absorption by the parent diatomic halogen. For IO, this was overcome by long exposures and by the high temperature which substantially dissociated $I2$ to atoms. Since the bond strengths of BrO and Clo are well established, a simple quantitative measurement of the absorption strength at a single convenient temperature should suffice to determine the transition probability for these oxides.