Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.641065
Title: Crystallographic studies related to the use of mandelic acid and camphor-10-sulphonic acid as resolving agents
Author: Armstrong, Susan
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 1991
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Please try the link below.
Access from Institution:
Abstract:
This work describes and compares the crystal structures of diaslereomeric pairs of compounds which could result from resolutions of neutral amino acids by both mandelic acid (MAN) and camphor-10-sulphonic acid (CSA). Chapter 2 details experimental methods used. Tables list the outcomes of NMR and mp analysis of crystals to suggest whether or not they were the desired products. Section 2.13 describes the conventions employed for the labelling of atoms. Chapter 3 describes the determination of crystal structures of six MAN-amino acid complexes, and experimental data which suggested whether a 1:1 compound had been made in these and other attempts. Crystallographic data and tables listing atomic coordinates and thermal parameters are included in each of the six sections describing structures. Chapter 4 details evidence that MAN molecules were undissociated. The molecular conformations are compared with those of other known structures, and the molecular packing arrangements; hydrophobic interactions; and hydrogen bonding schemes are given. Only 2 pairs of diastereomcric complexes were obtained. Tables listing bond lengths, angles and torsion angle are given at the end of the chapter. Chapter 5 adopts the same format as chapter 3 and describes 5 simple salts and 4 amino acid salts of CSA. Progress towards the unsuccessful preparation and structure determination of other amino acid-CSA salts is described in section 5.10. The absolute configuration of (+ )-CSA was verified as described in section 5.1. Chapter 6, like chapter 4, is about molecular conformations, molecular packing arrangements and hydrogen bonds. A single pair of diastereomcric salts was prepared successfully to allow comparison of their crystal structures (MET/CSA). The structure of one other salt, PHG/CSA, was particularly important, since the molecular recognition that takes place is quite clear cut and results in the absolute preference for one diastcreomcr, R-PHG-1S-4R-CSA, over the other, and indeed makes CSA a particularly good resolving agent for PHG. The source of conformational comparisons between CSA molecules was the simple salts prepared in this work. Tables listing bond lengths, angles and torsion angles are to be found at the end of the chapter. Packing diagrams are included at the end of section 6.3 and part packing diagrams showing only the hydrophilic parts of the structures in section 6.4. Chapter? analyses some resolution attempts, in which powder diffraction was the major tool. Photocopies of powder photographs are included. The results of resolutions were examined in the light of an understanding of the numbers of hydrogen bonds and the packing arrangemenls determined in the single crystal work.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.641065  DOI: Not available
Share: