Shades of phototoxicity in fluorescent imaging agents (that are not supposed to be phototoxic).

This article is a highlight of the paper by Huang et al. in this issue of Photochemistry and Photobiology. It describes shades of phototoxicity in fluorescent imaging agents that are not intended to be phototoxic.

Tuning the O Oxidation of a Phenol at the Air/Solid Interface of a Nanoparticle: Hydrophobic Surface Increases Oxophilicity.

Although silica surfaces have been used in organic oxidations for the production of peroxides, studies of airborne singlet oxygen at interfaces are limited and have not found widespread advantages. Here, with prenyl phenol-coated silica and delivery of singlet oxygen (O) through the gas phase, we uncover significant selectivity for dihydrofuran formation over allylic hydroperoxide formation. The hydrophobic particle causes prenyl phenol to produce an -hydroperoxide intermediate with an internally protonated oxygen atom, which leads to dihydrofuran formation as well as O atom transfer.