Molecular modelling and crystallographic techniques have been applied to the study of organic molecules used as friction modifiers and metal salt transport reagents. The accuracy of several empirical force fields has been evaluated by calculating low energy conformations of 3-(4-methylbenzoyl) propionic acid and tri acetyl glycerol. These were compared with the crystal structures of related molecules obtained from the Cambridge Structural Database, which contained either the 4-keto-carboxylate moiety or were tri esters of glycerol. Further validation has been carried out by comparing the force field predicted low energy conformations of propionic acid and ethylene glycol with the results of <i>ab initio </i>calculations either obtained from the literature or performed in house. Liquid phase molecular dynamics calculations have been carried out under conditions of constant volume and temperature and of constant temperature and pressure in order to investigate structure – activity relationship in films of physisorbed friction modifiers based on fatty esters of glycerol. We are able to make proposals about how the varying efficacy of mono, di and tri esters of glycerol arises from their structure. The crystal structures of novel complexes of model extractants for salts of base metals have been determined and analysed. These complexes fall into one of four classes: 1) Complexes containing salicylaldoxime ligands; 2) Complexes based on hexadentate tris-salicylaldimine ligands; 3) Complexes based on bipodal hexadentate ligands salicylaldimine ligands; 4) Complexes based on coordination of two tridentate salicylaldimine ligands. For classes 3) and 4) we have investigated the possibility of isomerism using the results of our structure determination and structures obtained from the Cambridge Structural Database. We have also investigated the possibility of a combined molecular dynamics/mechanics approach to asses the efficiency of phase transfer for this type of complex.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:649162 |
| Date | January 2005 |
| Creators | Davidson, James E. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/13575 |
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