Is water the best or the worst solvent for [2 + 4] cycloadditions of singlet oxygen to aromatic compounds?
Abstract
An accelerating effect of water, greater than two orders of magnitude, is observed for the photo-oxygenation of disodium 3,3′-(1,4-naphthylidene)dipropionate at variance with the current assumption on the constancy of the rate constant of 1O2[2 + 4] cycloadditions in various solvents.