Doubly charged cluster ions [(NaCl)m(Na)2]2+: magic numbers, dissociation, and structure

摘要: Doubly charged sodium chloride cluster ions [(NaCl)m(Na)2]2+ with m = 11–62, were produced by electrospray ionization and examined tandem mass spectrometry in a quadrupole ion trap. Variations the intensity size indicate existence of magic numbers at 11, 12, 17, 20, 21, 26, 30, 34, 36, 44, 54, 61. The number clusters studied collision-induced dissociation (CID). largest (m > 35) fragment mainly neutral losses. Cluster containing 19–35 NaCl molecules are prone to fission charge separation form singly (a regular crystallite comprised × b c ions, where a, b, small odd integers) along other lower abundance clusters. Small doubly < 19) could not be isolated for study unless an unusually large isolation window (10–30 mass/charge units) was used. Structures three types proposed account behavior clusters: (1) combination blocks, block is c, including special case perfect sheet 1), (2) merged (3) crystallites single-point defects − 1, integers). Electrospray (ESI) proves good way generate salt gas phase trap well suited their characterization.