Thesis
Investigations of s-block organoelement (nitrogen, oxygen) chemistry
- Creator
- Rights statement
- Awarding institution
- University of Strathclyde
- Date of award
- 2024
- Thesis identifier
- T16923
- Person Identifier (Local)
- 202092937
- Qualification Level
- Qualification Name
- Department, School or Faculty
- Abstract
- It is an exciting time to be researching main group chemistry, especially s-blockchemistry, as recent years have witnessed the opening up of several new fronts in thedevelopment of the Group 1 and Group 2 chemistry. Partly industrial (sponsored byInnospec Ltd) and partly fundamental, this project reflects such diversity.The industrial part considered a negative aspect of these metal compounds, that sodiumcarboxylate salt deposits cause a range of problems in diesel engines includingmisfiring, injector malfunction and failure, causing increased fuel consumption andemissions. Following up previous work by the group determining the structures ofrelevant long chain sodium carboxylates, here the focus turned to one possiblecontamination source of them in ammonium carboxylates, the structural chemistry ofwhich has been enhanced by 16 crystal structures of one-dimensional zig-zagpolymeric chains constructed of 12-, 26-, or 34-membered ring systems.Much of the project's work was devoted to preparing tripodal modifications of thecommon NacNacH (Me, Dipp) molecule derived from 2,6-diisopropylphenyl-?methyldiketimine. Lithiation of NacNacH, followed by reactions with isocyanates,isothiocyanates and a carbodiimide, and aqueous work-up accessed tripodal NacNacvariants with N,N,N,O; N,N,N,S; or N,N,N,N potential dentation sites. Many werecrystallographically characterised, while distinct ligating modes of these new ligandswere elucidated through crystal structures of their lithiated precursors.Surprisingly, literature searches revealed that LiNacNac and NacNacMg(TMP)(tetramethylpiperidide) have rarely been reported in reactions with common carbonylsubstrates. Therefore, metal products from reactions with benzaldehyde and assortedketones were synthesised and crystallographically characterised. Extended to rubidiumand caesium via reaction of their HMDS (hexamethyldisilazide) complexes withbenzaldehyde and acetophenone, revealed a diversity of eye-catching structuraloutcomes in an enolate with a hexagonal prismatic network, two dienolates withdistinct ladder motifs, and two ?-imino-alkoxides comprising zig-zag chains of metal–oxygen bonds in infinite cages.
- Advisor / supervisor
- Robertson, Stuart
- Mulvey, Robert
- Barker, Jim
- Resource Type
- Note
- Previously held under moratorium from 14/05/2024 to 14/05/2026.
- DOI
- Funder
- Embargo Note
Relations
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File | 2024-08-27 | Embargo |