Atomically resolved single-molecule triplet quenching

Triplet-state lifetime quenched by oxygen Little is known about the atomistic mechanism that nature uses to mitigate the destructive interaction of triplet-excited pigment chromophores with omnipresent oxygen. Peng et al. tackled this challenge by developing a technique based on conducting atomic force microscopy to populate and track triplets in a single pentacene molecule, a model ϖ-conjugated system, placed on a sodium chloride surface (see the Perspective by Li and Jiang). The authors show how the triplet-state lifetime can be quenched in controllable manner by atomic-scale manipulations with oxygen co-adsorbed in close vicinity. The presented single-molecule spectroscopy paves the way for further atomically resolved studies of triplet excited states that play an important role in many other fields, such as organic electronics, photocatalysis, and photodynamic therapy. Science , abh1155, this issue p. 452 ; see also abj5860, p. 392