Figure 3.

Relative fluorescence of isomers 1–4 (Figure 1) in MeCN (80% v/v) and 10 mM HCOONH₄ buffer, pH = 7.4 (20% v/v). Yellow bars: starting materials. Green bars: after complete photolysis of the starting diazoketones. The numbers on top of the bars show the fluorescence quantum yields for the starting compounds and their increase upon photolysis to mixtures containing α-diketones as the main products (see Figure S3).