O‐nitrobenzyl photochemistry: Solution vs. solid‐state behavior

The efficiency of various 2‐nitrobenzyl groups in the photogeneration of carboxylic acid from nitrobenzyl esters has been determined, and the solution vs. solid polymer matrix photochemistry is compared. Generally, the quantum yield for photoreaction is lower in the solid state, probably due to decreased conformational mobility. The substitution that affords the largest increase in quantum yield (ϕ) is at the α‐carbon atom. The value of ϕ for α‐methyl‐2‐nitrobenzyl trimethylacetate in solution is 0.65 vs. 0.13 for the parent 2‐nitrobenzyl ester.