σ-Complexes of Copper(I)
File(s)
Author(s)
Hicken, Alex
Type
Thesis
Abstract
Three new bent {CuL2} fragments of copper(I) supported by β–diketiminate ligands have been
synthesised and characterised in the solid state, in solution and via DFT calculations. The
suitability of these {CuL2} fragments to be used as precursors for the formation of σ-complexes
with an E–H (E = B) or M–H (M = Zn, Al, Mg, Ca, Au, W) bond has been investigated. Their
electronic properties and bent confirmation make them ideal fragments for the stabilisation of σ-complexes of copper(I).
A range of σ-complexes of the type Cu–H–E and Cu–H–M (E = B, M = Zn, Al, Mg, Ca, Au)
have been isolated and characterised in the solid state, in solution and via DFT calculations. In
the case of E = B and M = Zn, Mg and Ca, an insight into their decomposition to 4 coordinate
M(Ln)2 species’ (Ln = β–diketiminate ligand) has been summarised. Increased Cu---M bond
character is observed when the heavier transition metal tungsten is employed, and these
complexes can be considered as well defined heterobimetallic hydride species of Cu–H–W.
The reactivity of heterobimetallics of the type Cu–H–E and Cu–H–M, whereby E = B and
M = Zn, W has been investigated through ligand exchange reactions. σ-Complexes of
Cu–H–Au, along with mixtures of isolable group 10 fragments and the gold hydride complex
IPrAu–H (IPr = 1,3-di(2,6-diisopropylphenyl)imidazol-2-ylidine), have shown to be selective in the reduction of carbon dioxide to a formate equivalent with HBPin (HBPin = pinacolborane).
In summary, this thesis provides new insights into the synthesis, characterisation, stability and
reactivity of σ-complexes of copper(I).
synthesised and characterised in the solid state, in solution and via DFT calculations. The
suitability of these {CuL2} fragments to be used as precursors for the formation of σ-complexes
with an E–H (E = B) or M–H (M = Zn, Al, Mg, Ca, Au, W) bond has been investigated. Their
electronic properties and bent confirmation make them ideal fragments for the stabilisation of σ-complexes of copper(I).
A range of σ-complexes of the type Cu–H–E and Cu–H–M (E = B, M = Zn, Al, Mg, Ca, Au)
have been isolated and characterised in the solid state, in solution and via DFT calculations. In
the case of E = B and M = Zn, Mg and Ca, an insight into their decomposition to 4 coordinate
M(Ln)2 species’ (Ln = β–diketiminate ligand) has been summarised. Increased Cu---M bond
character is observed when the heavier transition metal tungsten is employed, and these
complexes can be considered as well defined heterobimetallic hydride species of Cu–H–W.
The reactivity of heterobimetallics of the type Cu–H–E and Cu–H–M, whereby E = B and
M = Zn, W has been investigated through ligand exchange reactions. σ-Complexes of
Cu–H–Au, along with mixtures of isolable group 10 fragments and the gold hydride complex
IPrAu–H (IPr = 1,3-di(2,6-diisopropylphenyl)imidazol-2-ylidine), have shown to be selective in the reduction of carbon dioxide to a formate equivalent with HBPin (HBPin = pinacolborane).
In summary, this thesis provides new insights into the synthesis, characterisation, stability and
reactivity of σ-complexes of copper(I).
Version
Open Access
Date Issued
2018-06
Date Awarded
2019-01
Copyright Statement
Creative Commons Attribution NonCommercial Licence
Advisor
Crimmin, Mark
Sponsor
Natural Environment Research Council (Great Britain)
Publisher Department
Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)