Figure 4.

From top to bottom: ¹H NMR spectra of 10 mM C₄C₁OQ⁺, 3.3 mM C₄C₁OQ⁺ + 6.7 mM SCX4 mixture, 10 mM C₁C₄OQ⁺, and 3.3 mM C₁C₄OQ⁺ + 6.7 mM SCX4 mixture in D₂O at 298 K. The asterisks denote the peaks related to the SCX4 protons; (A,B) correspond to two distinct spectral ranges. The small triplet at 1.05 ppm results from an impurity present in the SCX4 compound. (The spectrum of neat SCX4 solution displays this small contribution.)