Abstract
To explore if the catalytic activity of single-metal species in halometallate catalysts can be enhanced with mixed-metal species, aluminum and gallium were simultaneously introduced to prepare a mixed-metal ionic liquid (IL) through a one-pot reaction of [HN222]Cl, AlCl3, and GaCl3 in various amounts. The Lewis acidity in Friedel-Crafts acylation and alkylation reactions of these IL compositions were evaluated and all mixed-metal [HN222][xAlCl3 + (2-x)GaCl3]Cl ILs exhibited higher catalytic activity than AlCl3, GaCl3, [HN222][Al2Cl7], or [HN222][Ga2Cl7]. The broadening in 27Al nuclear magnetic resonance (NMR) of these ILs indicates the presence of dynamic anionic species, whereas matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) and acetonitrile-probed Fourier transform infrared (FT-IR) analyses correlates the structure-activity relationship, for instance, identifying the presence of mixed-metal-containing [Cl2GaOClAlClOGaCl2]- species in the better-performing ILs.
Original language | English |
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Pages (from-to) | 9789-9793 |
Number of pages | 5 |
Journal | ACS Catalysis |
Volume | 9 |
Issue number | 11 |
DOIs | |
State | Published - Nov 1 2019 |
Keywords
- Friedel-Crafts acylation/alkylation
- Lewis acid catalyst
- chloroaluminate
- chlorogallate
- double salt ionic liquids