Use this URL to cite or link to this record in EThOS:
Title: The chemistry of the hypersilyl and related ligands
Author: Chan, W. T. K.
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 2009
Availability of Full Text:
Full text unavailable from EThOS.
Please contact the current institution’s library for further details.
This thesis is mainly focused on the investigation of the chemistry and reactivity of the hypersilyl ligand {[(Me3Si)3Si]-}, and the rationalisation of the use of siloxanes as precursors ([(R2SiO)n]). A total of ten new compounds have been prepared from these studies, and X-ray crystallography forms a central basis of the analysis of these species, along with NMR spectroscopy and various other analytical techniques. The first novel compound described is [(Ph3Si)(Me3Si)2SiK.18-crown-6] (3). Despite isolating 3 in pure both crystalline and powder form the difficulty in synthesising the compound in large scale meant that its reactivity could not be investigated fully. A series of Si-M complexes was made in the form of [(Me3Si)3Si.MX3]-[K.18-crown-6]+ (4-6, M = Al or Ga, X = Cl or Br), as well as [(Ph3Si)(Me3Si)2Si.GaCl3]-[K.18-crown-6]+ through the reaction of the respective silyl anion with the corresponding group 13 halides. Due to yield considerations, 6 was chosen as a precursor to study the thermal decomposition behaviour of this type of compounds. The reaction between (Me3Si)3SiK.18-crown-6 (1a) with (P4) led to the formation of the unusual {P8[(Me3Si)3Si]2.K.18-crown-6}-[K.18-crown-6.(THF)2]+ (8). The discovery of 8 allows an investigation into the relatively poorly understood mechanism for this type of reaction, and a proposed mechanism, supported by computational calculations, is discussed. The reaction between hypersilyl potassium (1a) and mesityl nitrile gave 6,8-dimethyl-1-amino-3-mesityl-isoquinoline. Finally, the unexpected formation of [2-PySi(Me)2LiO]6 and {[18-crown-6.]GaCl4} are also described.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available