Temperature effect on radiative lifetimes: the case of singlet oxygen in liquid solvents.

A change in solvent can have an appreciable effect on the rate constant for the O2(a(1)Δg) → O2(X(3)Σg(-)) radiative transition at ~1275 nm. The data thus obtained have played an important role in understanding mechanisms by which environment-dependent perturbations can influence forbidden electronic transitions. We now report that the rate constant for O2(a(1)Δg) radiative deactivation, kr, also responds to changes in temperature.

Reaction of singlet oxygen with tryptophan in proteins: a pronounced effect of the local environment on the reaction rate.

Singlet molecular oxygen, O(2)(a(1)Δ(g)), can influence many processes pertinent to the function of biological systems, including events that result in cell death. Many of these processes involve a reaction between singlet oxygen and a given amino acid in a protein. As a result, the behavior of that protein can change, either because of a structural alteration and/or a direct modification of an active site.

Singlet oxygen's response to protein dynamics.

Singlet molecular oxygen, O(2)(a(1)Δ(g)), is an intermediate in a variety of processes pertinent to the function of biological systems, including events that result in cell death. Many of these processes involve a reaction between singlet oxygen and a given protein. It is acknowledged that the behavior of a protein can change upon reaction with singlet oxygen, as a result of a structural alteration and/or a direct chemical modification of an active site.

Temperature effects on the solvent-dependent deactivation of singlet oxygen.

Singlet molecular oxygen, O(2)(a(1)Delta(g)), is an intermediate in a variety of oxygenation reactions. The reactivity of singlet oxygen in a given system is influenced, in part, by competitive solvent-dependent channels that deactivate singlet oxygen in a nonradiative process. It has long been considered that these deactivation channels depend only slightly on temperature.