UMI  
ProQuest® Dissertations & Theses
The world's most comprehensive collection of dissertations and theses. Learn more...
ProQuest  
 
 
Spectroscopic investigations and analytical applications of enantiomeric interactions
by Yu, Shaofang, PhD, MARQUETTE UNIVERSITY, 2006, 0 pages; 3244571
 

Abstract: Chiral recognition is an important subject in various fields including chemistry, biology, pharmaceutical, and medical sciences. Even though various chiral selectors have been developed for chiral separations in HPLC, Capillary Electrochromatography and Capillary Electrophoresis, compare to the large amount of available enantiomers, chiral selectors are still in great demand. Furthermore, to date, induced chiral separation mechanisms have not been thoroughly studied. Chiral ionic liquids (CILs) can be used as chiral solvents and may promote chiral discrimination. In Chapter 1, a group of over 15 pairs of CILs were synthesized through one step metathesis reaction. They were studied by NMR, LC-MS, DSC, TGA and X-Ray crystallography. X-Ray crystallography of some of the CILs indicates that C-H···O hydrogen bonds provide dominating forces for crystal packing. NMR studies show that enantiomers of these CIL pairs interact differently with tBuCQN-HCl which is a chiral selector. And chiral anions of these CILs have good chiral discrimination ability on racemic cations. And also, these CILs undergo aggregation in solution in a similar way as surfactants do. In Chaper 2, a new method based on a Near-Infrared spectrophotometric technique has been developed to determine critical micelle concentration (CMC) of surfactants in ionic liquids. Comparing to other CMC determination methods, this NIR method is universal, sensitive, nonintrusive and nonadditive. CMC values of various surfactants including CTAB, SDS, TritonX-100, Brij-35, Brij-700, Tween-20, SB-12, S133-10 and AOT in aqueous solvent, organic solvent or ionic liquids determined by this method agree very well with those determined by other methods. In Chapter 3, to approach the mechanism of chiral interaction, a new method based on UV-vis was developed. Chiral selector carbamoylated derivatives of quinine (tBuCQN) and 3,5-dinitrobenzoyl derivatives of Leucine (DNB-Leu) enantiomers were selected. Derivatives of Leucine were used as substrate. Binding constants of tBuCQN and these Leucine derivatives in solvents with different polarities were determined with either UV-vis or NMR spectroscopic methods to determine the function of different groups and solvent effects. Results obtained have been successfully applied to capillary electrophoresis for chiral separation with tBuCQN as a chiral selector.

 
Advisor: Tran, Chieu D.
School: MARQUETTE UNIVERSITY
Source: DAI-B 67/12, p. 7057, Jun 2007
Source Type: PhD
Subjects: Analytical chemistry
Publication Number: 3244571
     
Adobe PDF Access the complete dissertation:
 

» Find an electronic copy at your library.
  Use the link below to access a full citation record of this graduate work:
  http://gateway.proquest.com/openurl%3furl_ver=Z39.88-2004%26res_dat=xri:pqdiss%26rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation%26rft_dat=xri:pqdiss:3244571
  If your library subscribes to the ProQuest Dissertations & Theses (PQDT) database, you may be entitled to a free electronic version of this graduate work. If not, you will have the option to purchase one, and access a 24 page preview for free (if available).

 
 
 

About ProQuest Dissertations & Theses
With over 2.3 million records, the ProQuest Dissertations & Theses (PQDT) database is the most comprehensive collection of dissertations and theses in the world. It is the database of record for graduate research.

The database includes citations of graduate works ranging from the first U.S. dissertation, accepted in 1861, to those accepted as recently as last semester. Of the 2.3 million graduate works included in the database, ProQuest offers more than 1.9 million in full text formats. Of those, over 860,000 are available in PDF format. More than 60,000 dissertations and theses are added to the database each year.

If you have questions, please feel free to visit the ProQuest Web site - http://www.il.proquest.com - or call ProQuest Hotline Customer Support at 1-800-521-3042.



Copyright © 2007 ProQuest. All rights reserved. Terms and Conditions

ProQuest