Figure 1.

IR spectrum of products of the reaction of 1,4-dichlorobutane vapors with the H{Cl₁₁} acid (blue) and an isolated spectrum of the formed salt (CH₂CH₂)₂Cl⁺{Cl₁₁^–} (red), after the removal of 1,4-dichlorobutane vapors and gaseous HCl by evacuation. The spectrum of decomposition products of the salt (CH₂CH₂)₂Cl⁺{Cl₁₁^–} when heated at 150 °C is black. The most distinctive bands of the {Cl₁₁^–} anion are marked with asterisks.