Figure 2.

Irradiation of azibenzil (PhCOCN₂Ph) dissolved in aqueous acetonitrile (80% acetonitrile, 20% water, v/v) with HCOONH₄ buffer (pH 7.3) results in full conversion to a new substance (amide 16, see Figure S2) with the same retention time but without absorption maximum at 319 nm. (A) Absorption changes upon irradiation; inset: transient at 319 nm. (B) Chromatograms (2D maps) of the sample before (left) and after (right) irradiation. (C) Chromatogram at 260 nm (a shift was introduced for clarity); inset: absorption spectra of the main peaks.