Cross, Mathew  ORCID: https://orcid.org/0000-0003-3495-442X
  
(2025)
Group 8 & 9 catalysts for the dehydropolymerisation of amine-boranes.
    PhD thesis, University of York.
ORCID: https://orcid.org/0000-0003-3495-442X
  
(2025)
Group 8 & 9 catalysts for the dehydropolymerisation of amine-boranes.
    PhD thesis, University of York.
  
	   
Abstract
Chapter 1: This introductory chapter covers topics that are necessary to understand 
the research background upon which this thesis is built. These include fundamental 
amine-borane and polyaminoborane chemical properties, the origin of catalytic routes 
to polyaminoborane formation, the potential applications of polyaminoboranes, the 
mechanisms of amine-borane dehydropolymerisation and the general concept of metal 
ligand cooperative catalysis.
Chapter 2: In the second chapter, the activation and deactivation pathways of group 9 
metal ligand cooperative amine-borane dehydropolymerisation catalysts are 
investigated, primarily focussing on rhodium metal-ligand cooperative aminophosphine 
complexes (such as Rh(iPr-PNHP)H2Cl) that have recently been reported by the Weller 
group. The slow spontaneous dissociation of amine-boranes in solution is discussed 
and its poisoning effect on amine-borane dehydropolymerisation catalysts, forming 
borohydride complexes. This is related to the as-yet unsolved problem that the 
substrate scope for previously reported amine-borane dehydropolymerisation catalysts 
is limited primarily to the parent ammonia-borane and its N-methyl derivative.
Chapter 3: In this chapter the structure, mechanism and speciation are investigated 
for amine-borane dehydropolymerisation catalysts based upon the previously reported 
but broadly overlooked ruthenium aminophosphine precatalyst 
Ru(iPr2PCH2CH2NH2)2Cl2. The highly unusual and reactive square-planar, d6 and low�spin precatalyst Ru(iPr2CH2CH2NH)2 is characterised and its electronic structure 
discussed. Such precatalysts are shown to exhibit the highest-yet reported rate of 
amine-borane dehydropolymerisation, and this rapid catalysis is utilised for the 
synthesis of high molecular weight N-methyl polyaminoborane. ethyl and propyl 
polyaminoboranes. Parts of this chapter are published as a communication in an 
Angew. Chem. Int. Ed. article. 
Chapter 4: This final discussion chapter covers the first report of selective N-ethyl and 
N-propyl amine-borane catalytic dehydropolymerisation, forming the N-ethyl and N�propyl polyaminoboranes utilising the ruthenium catalyst discussed in chapter 3 
(Ru(iPr2PCH2CH2NH2)2Cl2). The possible routes of catalyst deactivation when using 
these amine-boranes as substrates is also discussed.
Chapter 5: Experimental data, figures, tables and methods.
Metadata
| Supervisors: | Andrew, Weller | 
|---|---|
| Related URLs: | |
| Keywords: | Catalysis, dehydrogenation, cooperativity, boron, polymer | 
| Awarding institution: | University of York | 
| Academic Units: | The University of York > Chemistry (York) | 
| Depositing User: | Mr Mathew Cross | 
| Date Deposited: | 03 Sep 2025 08:25 | 
| Last Modified: | 03 Sep 2025 08:25 | 
| Open Archives Initiative ID (OAI ID): | oai:etheses.whiterose.ac.uk:37359 | 
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