Bulky Counterions: Enhancing the Two‐Photon Excited Fluorescence of Gold Nanoclusters

The front cover artwork is provided by the SpectroBio research group of the Institut Lumière Matière in Lyon. The image shows the structure of Au15(SR)13, a thiolated (SR) gold nanocluster and a pictoral view of ion‐pairing of surface ligands with bulky counterions. With such ion‐pairing, a 30‐fold increase in two‐photon excited fluorescence signal at ≈600 nm can be observed. Read the full text of the article at 10.1002/cphc.201701186. “We show that by an appropriate choice of bulky counterions and of solvent, a 30‐fold increase in two‐photon excited fluorescence (TPEF) signal at ≈600 nm for gold nanoclusters can be obtained…” This and more about the story behind the front cover can be found in the Communication at 10.1002/cphc.201701186.