Direct analysis of metal halides by electron-impact mass spectrometry

Abstract

thiourea in the solution to avoid the reverse reaction between thiourea and gold(III) which produced the gold(I) thiourea species. Oxidation of thiourea in acidic solution to give sulfate ion required the action of a vigorous oxidant in a boiling solution (9). Aqua regia (3 parts concentrated hydrochloric acid to 1 part concentrated nitric acid) proved to be effective for this dual purpose. The higher the concentration of thiourea in the solution, the more aqua regia had to be added to ensure that the gold remained in the gold(III) form; this relationship had to be determined empirically. The quantity of concentrated aqua regia required to oxidize the thiourea in 10 ml of 0.1M sulfuric acid solution in shown in Figure 1. The destruction of the thiourea was marked by an effervescence in the solution (distinct from boiling) and the evolution of nitrous fumes; at higher concentrations of thiourea, this effervescence became very vigorous. A slight cloudiness in the liquor was usually the result of the addition of insufficient aqua regia; this shortfall was made good before proceeding

A theoretical study of SnF2+, SnCl2+, and SnO2+ and their experimental search

“…Whereas SnF 2+ is apparently a novel gas-phase diatomic dication, studies by Matsumoto et al of metal chlorides using conventional electron-impact mass spectrometry also provided a first experimental evidence of the species SnCl 2+ . 10,11 To our knowledge, no previous theoretical investigation characterizing these three species and thus supporting the experimental findings seems to be available in the literature.…”

Effectiveness of Different Ligands on Silane Precursors for Ligand Exchange to Etch Metal Fluorides

“…4 and ZnF 2 powder at 475 °C produced ZnCl 2 + ion signals as displayed in Figure4. ZnCl 2 + is the parent molecular ion of ZnCl 2 33. The appearance of ZnCl 2 + ion signals indicates F/Cl exchange between the SiCl 4 precursor and the ZnF 2 surface.…”