Document Type Master's Dissertation Author Mampa, Richard Mokome URN etd-02092006-155713 Document Title X-ray and NMR spectropscopic studies of selected heterocyclic compounds of phosphorus and nitrogen Degree MSc (Chemistry) Department Chemistry Supervisor
Advisor Name Title Prof T A Modro Committee Chair Keywords
- chemistry analytic heterocyclic compounds ohospho
- chemistry analytic heterocyclic compounds nitrogen
Date 2001-09-01 Availability unrestricted AbstractA 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.
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Please cite as follows:
Mampa, RM 2000, X-ray and NMR spectroscopic studies of selected heterocyclic compounds of phosphorus and nitrogen, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-02092006-155713/ >
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