Study of the intrinsic properties of imidazolium ionic liquids via mass spectrometry with atmospheric pressure ionization

Author(s)

Fabiane Manke Nachtigall

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 2009-05-10

Examining board members

Marcos Nogueira Eberlin; Brenno Amaro da Silveira Neto; Rodinei Augusti; Fernando Antonio Santos Coelho; Fábio Cesar Gozzo

• Advisor: Marcos Nogueira Eberlin

Abstract

In order to understand the intrinsic properties of imidazolium ionic liquids, studies of dissociation and distillation mechanisms were developed. The intrinsic strength of hydrogen bonds and formation and characterization of carbenes from these compounds were also investigated. Such studies were conducted by API (Atmospheric Pressure Ionization) mass spectrometry techniques such as ESI-MS(/MS) (Electrospray Ionization Mass Spectrometry) and APCI-MS(/MS) (Atmospheric Pressure Chemical Ionization Mass Spectrometry) which are soft ionization techniques allowing the analysis of compounds by direct infusion of the solution of interest. For these studies, imidazolium cations with different substituent at positions N-1, N-3 and C-2 and different anions as counter ions were selected. The objective was to test how these changes in the chains would affect the intrinsic properties studied. From the results of the work fragmentation mechanisms for a wide range of imidazolium ionic liquids were proposed, as well as a mechanism for the distillation of some of these compounds. Measurements were made to order the intrinsic strength of hydrogen bonding for different cations. Further information was obtained about the formation and characterization of carbenes from di-, tri-and tetra-imidazolium ionic liquids. (AU)