Fast Atom Bombardment Mass Spectrometry of Low Temperature Chloroaluminate and Chlorogallate Melts
Abstract
Fast atom bombardment (FAB) mass spectrometric analyses of room temperature chloroaluminate and chlorogallate molten salts are described. Melts composed of AICI3or GaCI3with 1-butylpyridlnlum chloride (BPC) or 1-methyl-3-ethyl-Imldazollum chloride (MEIC) were Investigated to determine the nature of the Al or Ga species as a function of Lewis acidity. Acidic melts contain a molar excess of AICI3or GaCI3, whereas basic systems have a molar excess of the organic chloride. Mass spectra of negative Ions were selected by using a Kratos MS80RFA, double focusing, forward geometry mass spectrometer. Anions such as AlCl4-, Al2Cl7-, Al3Cl9-, GaCl4-, and Ga2Cl7- were detected along with sub-valent monomer, dimer, and mixed-valent species. In addition, various oxychloro and hydroxychloro species of Al and Ga have been Identified as well as (cation—dlanion) aggregate Ions. Results obtained reflect the surface condensed phase chemistry and gas phase reaction pathways established by the energy Imparted by the FAB ionization process. © 1988, American Chemical Society. All rights reserved.