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Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry
Published on: October 18, 2019
A (-)-menthyl bonded silica phase for chiral separations: synthesis and solid state NMR characterization
B Lynch1, J D Glennon, C Tröltzsch
1Department of Chemistry, University College Cork, Cork, Ireland.
Analytical Chemistry
|June 7, 2011
Summary
A novel (-)-menthyl bonded silica phase was synthesized for chiral separations. This method exclusively yields a monomeric bonded organic silica phase, enabling effective enantiomeric separations in reversed-phase chromatography.
Area of Science:
- Materials Science
- Analytical Chemistry
- Organic Chemistry
Background:
- Silica-based stationary phases are crucial for chromatographic separations.
- Developing novel chiral stationary phases (CSPs) is essential for resolving enantiomers.
- Existing methods may result in non-monomeric or heterogeneous surface coverages.
Purpose of the Study:
- To synthesize a new (-)-menthyl bonded silica phase using a hydride silica intermediate.
- To characterize the surface species and coverage of the modified silica.
- To evaluate the efficacy of the new phase for enantiomeric separations in reversed-phase chromatography.
Main Methods:
- Hydrosilation of a hydride silica intermediate with a monoalkoxysilane.
- Synthesis of the hydride silica intermediate via reaction with silica gel.
- Characterization using solid-state (13)C and (29)Si CP-MAS NMR and DRIFT spectroscopy.
- Determination of surface coverage using quantitative analysis.
Main Results:
- A high surface coverage (4.4 μmol/m(2)) of SiH groups was achieved on the hydride silica intermediate.
- The modification procedure exclusively produced a monomeric coverage of SiH groups.
- The resulting (-)-menthyl bonded silica phase demonstrated successful chromatographic separation of enantiomers in reversed-phase mode.
Conclusions:
- The hydrosilation of a hydride silica intermediate is an effective method for preparing monomeric bonded silica phases.
- The new (-)-menthyl bonded silica phase is suitable for chiral separations.
- This approach offers precise control over surface modification for advanced chromatographic applications.
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