Possible isomers in ligand protected Ag<inf>11</inf> cluster ions identified by ion mobility mass spectrometry and fragmented by surface induced dissociation

This communication reports the identification of gas phase isomers in monolayer-protected silver clusters. Two different isomers of Ag11(SG)7- (SG-gulathione thiolate) with different drift times have been detected using combined electrospray ionization (ESI) and ion mobility (IM) mass spectrometry (MS). Surface induced dissociation (SID) of the 3- charge state of such clusters shows charge stripping to give the 1- charged ion with some sodium attachment, in addition to fragmentation. SID and collision induced dissociation (CID) for Ag11(SG)7- suggest different pathways being accessed with each method. SID was introduced for the first time for the study of monolayer-protected clusters.