Knowledge Bank

A remarkable property of the transition metal hexafluorides is their large electron affinity. In fact, the field of rare gas chemistry was initiated when it was discovered that $PtF6$ could oxidize $Xe.1$ It has been found that $IrF6$ in liquid or solid Xe has an intense new transition which begins about 10 000 {\AA} and continues at least until 5000 {\AA} where $IrF6$ has an intense charge transfer band. Observation of similar bands for $MoF6/Xe$ and $WF6/Xe$ at 3800 {\AA} and 2700 {\AA}, respectively, leads to the conclusion that the new transitions are charge transfer in nature. This data, along with a calorimetrically measured electron affinity for $WF6,2$ allows an estimation of the electron affinity of $IrF6$ and $MoF6$.