Photochemical hydrogen abstraction in 2-alkylpyrazinea 6-8 and 2-alkylpyridines 9-1 1 proceeds analogously to the process of eq 1. Hydroxylic solvent causes quantum yields for pyrazine fragmentation products (ap) to increase about 1 order of magnitude. Pyridine fragmentation takes place from both singlet and triplet states. Pyrazine fragmentations follow Stem-Volmer kinetics with modest bond strength selectivity (1: 30-1: 17 for Sa and Sc). ...
