Interparticle Delivery and Detection of Volatile Singlet Oxygen at Air/Solid Interfaces

An interparticle system has been devised, allowing airborne singlet oxygen to transfer between particle surfaces. Singlet oxygen is photogenerated on a sensitizer particle, where it then travels through air to a second particle bearing an oxidizable compounda particulate-based approach with some similarities to reactive oxygen quenching in the atmosphere. In atmospheric photochemistry, singlet oxygen is generated by natural particulate matter, but its formation and quenching between particles has until now not been determined. Determining how singlet oxygen reacts on a second surface is useful and was developed by a three-phase system (particle− air−particle) interparticulate photoreaction with tunable quenching properties. We identify singlet oxygen quenching directly by near-IR phosphorescence in the airborne state and at the air/particle interface for total quenching rate constants (kT) of adsorbed anthracene trapping agents. The air/solid interface kT of singlet oxygen by anthracene-coated particles was (2.8 ± 0.8) × 107 g mol−1 s−1 for 9,10-dimethylanthracene and (2.1 ± 0.9) × 107 g mol−1 s−1 for 9,10-anthracene dipropionate dianion, and the lifetime of airborne singlet oxygen was measured to be 550 μs. These real-time interactions and particle-induced quenching steps open up new opportunities for singlet oxygen research of atmospheric and particulate processes. Fil: Durantini, Andres Matías. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; Argentina. Brooklyn College; Estados Unidos Fil: Greer, Alexander. City University Of New York. The City College Of New York.; Estados Unidos. Brooklyn College; Estados Unidos