Photochemical Reaction Mechanisms of 2-Nitrobenzyl Compounds in Solution, I. 2-Nitrotoluene: Thermodynamic and Kinetic Parameters of theaci-Nitro Tautomer
phototriggers (`caged compounds'). The pH-rate profile for the decay of aci-1 in aqueous solution exhibits downward curvature at pH 3 – 4, which is attributed to pre-equilibrium ionization of the nitronic acid aci-1 to its anion 1− (pKa=3.57). Two regions of upward curvature, at pH ca. 6 and 6. A hird, irreversible Nef-type isomerization of aci-1 prevails in highly acidic solutions (pH<0). The equilibrium