Knowledge Bank

The vacuum ultraviolet absorption spectra of a variety of n,n dihalogenated compounds in the vapor phase, taken in the region from $40000cm-1$ (4.9 eV) to $83000cm-1$ (10.3 eV) will be presented. The transitions which occur In this In this region are thought to arise primarily from the specific combinations of halogen non-bonding $p$ orbitals which lie perpendicular to the M-X bonding axes. The $\sigma \ast \leftarrow n$ (M-X) and the first ns, np, and nd molecule Rydberg transitions of these orbitals will provide information as to the energy and configuration of the ground and excited states of the molecules in question. Starting with the spectra of CH$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$C1$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$,$\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$ and CH$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$Br$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$,$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ and CH$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$I$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$, subsequent spectral changes of other compounds in the series related to changes in symmetry, central atom and substituents about the central atom will be discussed. In the same regard, mixed halogen compounds will be related to the parent compounds.