Mass Spectrometry Analysis of the 1.5 nm Sphalerite-CdS Core of [Cd_(32)S_(14)(SC_6H_5)_(36)·DMF_4]

摘要

Electrospray ionization (ESI) mass spectrometry is a soft-ionization technique that allows analysis of exact structure, composition, and stability of solution phase materials by a gas-phase technique. We describe the application of ESI techniques for the analysis of a nanoscale material, [Cd_(32)S_(14)(SC_6H_5)_(36)·DMF_4]. The ～1.5 nm nanoscale cluster is composed of a ～1.2 nm sphalerite-phase (cubic) CdS core consisting of six tetrahedrally coordinated S atoms and four tetrahedrally coordinated Cd atoms. By MS/MS analysis of the parent ion, cleavage along the pseudo-<001> plane of the internal core is observed exposing a Cd-rich face analogous to a <001> plane in CdS. The fragmentation pattern of this nanoscale cluster provides insight into the potential fragmentation behavior of larger nanosized materials and suggests ESI may be a powerful technique for nanomaterial studies.