A full IH, l3C and 31P NMR assignments of phosphoric triamides 1-oxo-2,8-diphenyl-2,5,8-triaza-l-phosphabicyclo [3.3.0]octane (1), l-oxo-lO-phenyl-4,7,lO-triaza-2.3-benzo-l-phoshabicyclo [5.3.0]decane (2) and 1-oxo-4,7,lO-triaza-2,3,11,12-dibenzo-l-phosphabicyclo[5.5.0]dodecane (3) which have been recently synthesised was accomplished. The solution state NMR analysis of these compounds showed a number of interesting spin systems upon moving from 1→2→3, spanning from ABC to ABCDX spin systems where X is phosphorus nucleus. The three systems showed a high degree of rigidity in solution state, which made it possible to compare dihedral/torsion angles determined from solution state NMR with those of X-ray diffraction data. Both X-ray diffraction and NMR analysis supported the molecular conformations. A significant solvent effect was observed for solutions of compounds 1, 2 and 3 in benzene-d6 compared to solutions in chloroform-d1 and acetone. Benzene-d6 showed a generally upfield chemical shift of methylene protons in particular, and this is assumed to be due to different solvent-substrate interactions and to the magnetic anisotropic effect of the solvent. / Dissertation (MSc (Chemistry))--University of Pretoria, 2007. / Chemistry / unrestricted
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:up/oai:repository.up.ac.za:2263/27657 |
| Date | 09 February 2006 |
| Creators | Mampa, Richard Mokome |
| Contributors | Prof T A Modro, upetd@up.ac.za |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Dissertation |
| Rights | © 2000 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
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