Figure 5From: pH-controlled release of auxin plant hormones from cucurbit[7]uril macrocycle1H NMR spectra of 0.4 mM 2,4-D without and with 1.0 equivalent of CB[7]. They were recorded at pH 12.0 (spectra I and II) and pH 1.0 (spectra III and IV). The signal of r proton is not visible in the spectrum because it is overlying the water signal.Back to article page