Knowledge Bank

The infrared spectra of gaseous $IF3,IOF5$, and $IF7$ have been obtained from 30 to $4000cm-1$, and the Raman spectra of these compounds have been measured in the liquid phase. The spectra of $IF3$ and $IOF5$ are readily assigned on the basis of models with point group symmetry $C4v$, and their spectra are in close analogy to those reported for $BrF5,XeF4$, and $XeOF4$. In the case of $IF7$, its spectrum cannot easily be assigned on the basis of a model of $D5h$ symmetry, but appears to arise from a molecule of $C2v$ or lower symmetry which ``almost'' satisfies the $D5h$ selection rules.