Figure 11.

ATR IR spectra (with ATR corrections) of cations I/II (green) and III (red) in their crystal salts with anions {Cl₁₁^–} and {F₁₁^–}, respectively, and the IR spectrum (in transmission mode) of amorphous salt C₄H₇⁺{Cl₁₁^–} (black). To illustrate the spectrum of the {F₁₁^–} anion, an IR spectrum of the Cs{F₁₁} salt is given (gray). Two intense bands of the adsorbed CD₂Cl₂ molecules that were not removed by evacuation after we washed the amorphous salt with d₂-DCM are marked with an asterisk. Intense bands with unspecified frequencies belong to the anion. Broad intense absorption in the region ∼1400 cm^–1 is shaded in green.