Singlet oxygen chemistry in water. 2. Photoexcited sensitizer quenching by O2 at the water-porous glass interface.

Singlet Oxygen Chemistry in Water. 2. Photoexcited Sensitizer Quenching by O2 at the Waterâ‹TMPorous Glass Interface

Singlet oxygen chemistry in water: a porous vycor glass-supported photosensitizer.

Singlet molecular oxygen [1O2 (1Deltag)] is generated cleanly in aqueous solution upon irradiation of a heterogeneous complex, meso-tetra(N-methyl-4-pyridyl)porphine (1) adsorbed onto porous Vycor glass (PVG). The cationic photosensitizer 1 tightly binds onto PVG and gives a stable material, which does not dissociate 1 into the surrounding aqueous phase. The production of 1O2 was measured by mo...

Singlet Oxygen Generation on Porous Superhydrophobic Surfaces: Effect of Gas Flow and Sensitizer Wetting on Trapping Efficiency

We describe physical-organic studies of singlet oxygen generation and transport into an aqueous solution supported on superhydrophobic surfaces on which silicon-phthalocyanine (Pc) particles are immobilized. Singlet oxygen ((1)O2) was trapped by a water-soluble anthracene compound and monitored in situ using a UV-vis spectrometer. When oxygen flows through the porous superhydrophobic surface, s...

Generating singlet oxygen bubbles: a new mechanism for gas-liquid oxidations in water.

Laser-coupled microphotoreactors were developed to bubble singlet oxygen [(1)O(2) ((1)Δ(g))] into an aqueous solution containing an oxidizable compound. The reactors consisted of custom-modified SMA fiberoptic receptacles loaded with 150 μm silicon phthalocyanine glass sensitizer particles, where the particles were isolated from direct contact with water by a membrane adhesively bonded to the b...

Identification of quenchers of photoexcited States as novel agents for skin photoprotection.

Photooxidative stress is a key mechanism in UVA-induced skin photodamage. Photoexcited states of endogenous UVA chromophores such as porphyrins, melanin precursors, and cross-link-fluorophores of skin collagen exert skin photodamage by direct reaction with substrate molecules (type I photosensitization) or molecular oxygen (type II), leading to formation of reactive oxygen species. Based on our...