Photoinduced dissociation of anionic and electron detachment of dianionic gold clusters by use of a laser pointer

Abstract

Size-selected anionic and dianionic gold clusters have been stored in a Penning trap and irradiated with the green light of a laser pointer. As examples of special interest, the systems Au 7 − and Au 29 2− have been chosen. In particular, Au 7 −, a small gold cluster with closed electron shell, is observed to decay into Au 6 − and Au 5 − with a decay pathway branching ratio similar to that of Au 9 +. The dianionic cluster Au 29 2− shows electron detachment upon photoexcitation. This observation is in agreement with independent experiments [Stoermer et al., Int. J. Mass Spectrom. 201 (2001) 63], where Au 29 2− is found to be the smallest dianion produced by neutral monomer evaporation of hot dianionic gold clusters.