Highly unsaturated dendritic and conjugated systems of silicon by multiple transfer of Si=Si Units
File(s)
Author(s)
Jeck, Jonathan
Type
Thesis
Abstract
Stable disilenides, silicon analogues of vinyl anions, offer a valuable entry point to
unsymmetrically substituted disilenes of the A2
Si=SiAB (substituents A ≠ B) form otherwise
impossible to obtain. Disilenes, although kinetically stabilised by bulky substituents, readily
react with a broad range of substrates consuming the silicon double bond in a multitude of
addition reactions. This makes manipulations in the periphery of the disilene scaffold a
challenging task.
This thesis concentrates mainly on the synthetic approach to novel functionalised
unsymmetrically substituted disilenes by reaction of a disilenide with suitable precursors and
transformation of functionality in the presence of Si-Si double bonds.
The second major topic is the preparation of extended (conjugated) systems with multiple
Si=Si units using a disilenide as transfer reagent. Stable compounds featuring between one
and six Si=Si units were obtained and fully characterised including para-(halosilanyl)phenyl
disilenes, thiophenyl disilenes, aminophenyl disilenes as well as disilenyl functionalised
amine- and silane-centred dendritic molecules. Spectroscopic data for each class of
compounds is presented showing the influence of functional groups on the molecular
properties, especially the HOMO-LUMO gap.
unsymmetrically substituted disilenes of the A2
Si=SiAB (substituents A ≠ B) form otherwise
impossible to obtain. Disilenes, although kinetically stabilised by bulky substituents, readily
react with a broad range of substrates consuming the silicon double bond in a multitude of
addition reactions. This makes manipulations in the periphery of the disilene scaffold a
challenging task.
This thesis concentrates mainly on the synthetic approach to novel functionalised
unsymmetrically substituted disilenes by reaction of a disilenide with suitable precursors and
transformation of functionality in the presence of Si-Si double bonds.
The second major topic is the preparation of extended (conjugated) systems with multiple
Si=Si units using a disilenide as transfer reagent. Stable compounds featuring between one
and six Si=Si units were obtained and fully characterised including para-(halosilanyl)phenyl
disilenes, thiophenyl disilenes, aminophenyl disilenes as well as disilenyl functionalised
amine- and silane-centred dendritic molecules. Spectroscopic data for each class of
compounds is presented showing the influence of functional groups on the molecular
properties, especially the HOMO-LUMO gap.
Version
Open Access
Date Issued
2013-04
Date Awarded
2013-07
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Vilar Compte, Ramon
Publisher Department
Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)