Abstract
The research presented in this dissertation involves the synthesis, characterization, and application of novel anionic and cationic chiral molecular micelles in capillary electrophoresis (CE) for the separation of diverse chiral compounds. Chapter 1 presents brief overview of the surfactants, micelle polymer, CE and micellar electrokinetic chromatography (MEKC). Chapter 2 describes the simultaneous enantioseparation of eight single chiral center â-blockers using two novel leucine and isoleucine based polymeric surfactants. The simultaneous enantioseparation of multichiral center bearing â-blockers, nadolol and labetalol is described in chapter 3. A synergistic approach, using a combination of polysodium N-undecenoxycarbonyl-L-isoleucinate (poly-L-SUCIL) and sulfated â-CD showed dramatic enantioseparation of four stereoisomers of nadolol. On the other hand for labetalol, enantiomeric separation remains unaffected using the dual chiral selector system. Chapter 4 deals with the enantiomeric separation of the binaphthyl derivatives that was found to be influenced by pH, type and concentration of the background electrolyte as well as concentration of the polymeric surfactant. In chapter 5, characterization of five alkenoxy leucine-based surfactants with variations in chain length (C8-C11), polymerization concentration and degree of polymerization showed significant effects on the chiral resolution and efficiency of hydrophobic â-blockers. The synthesis and characterization of two positively charged amino acid derived chiral ionic liquids (ILs) and their corresponding polymers is presented in chapter 6. Chiral separation of two acidic analyte (difficult to resolve with anionic micelles) can be achieved with both monomers and polymers of ILs.
In chapter 7, the synthesis and detailed characterization of three pH independent amino acids derived (L-leucinol, L-isoleucinol and L-valinol) sulfated chiral polymeric surfactants is presented. These chiral sulfated surfactants are thoroughly characterized and the morphological behavior of polymeric sulfated surfactants is revealed using cryogenic high-resolution electron microscopy. The work clearly demonstrates for the first time the superiority of chiral separation in MEKC coupled to mass spectrometry at low pH. Finally, in chapter 8, six amino acid derived chiral surfactants with carboxylate and sulfate head groups were compared for enantioseparation of broad range of structurally diverse racemic compounds at neutral and basic pH conditions.
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