Fig. 3. CEST spectra collected at 37 °C for 4.9 mM aqueous solutions of 1 and 2 at pH 7.4, with ratios of 1 : 2 from 9 : 1 (blue) to 1 : 9 (red). The legend gives the independently obtained OCP of each sample (mV vs. NHE). Inset: expanded view of the relevant CEST peaks.