title: A study of novel ferrocenyl-phosphorus compounds

authors: Goodwin, Nicholas J.

abstract: The intent of this investigation was to use the distinctive characteristics of hydroxymethylphosphine chemistry in order to create new ferrocenyl-phosphorus compounds, as well as carry out investigations into both their electrochemistry and their potential for the production of ferrocene-containing polymers. 

The compound FcCH₂P(CH₂OH)₂ 1 (Fe = ferrocenyl) was prepared by the reaction of P(CH₂OH)₃ with [FcCH₂NMe₃]I, and FcCH₂PPh₂ 2 was prepared by a similar reaction. The compounds FcCH₂P(O)(CH₂OH)₂ 3, FcCH₂P(S)(CH₂OH)₂ 4, FcCH₂P(CH₂CH₂CN)₂ 5, FcCH₂P(CH₂NEt₂)₂ 6, FcCH₂P(O)(CH₂Net₂)₂ 7, [FcCH₂P(Me)(CH₂OH)₂]I 8, FcCH₂P(Me)CH₂OH 9, [(FcCH₂)₂P(CH₂OH)₂]Cl 10, (FcCH₂)₂PCH₂OH 11, FcCH₂P(H)PPh₂ 14 and FcCH₂P(O)PPh₂ 15 were prepared and characterised, and the compounds [FcCH₂P(Bz)(CH₂OH)₂]Br (Bz = benzyl) 12 and FcCH₂P(Bz)CH₂OH 13 were investigated though not fully characterised. The ferrocenylphosphine complexes cis- PtCl₂[FcCH₂P(CH₂OH)₂]₂ 16, PdCl₂[FcCH₂P(CH₂OH)₂]₂ 17, [Au{FcCH₂P(CH₂OH)₂}₂]Cl 18, RuCl₂(η⁶-C₁₀H₁₄)[FcCH₂P(CH₂OH)₂] 19 and RuCl₂ (η⁶-C₁₀H₁₄)(FcCH₂PPh₂) 20 were also prepared. X-ray crystal structure determinations were carried out for the compounds 1, 2, 4, 8, 18 and 20, and the solid-state hydrogen-bonding interactions present in the case of 1, 4, 8 and 18 were deduced. 

Hydrogen-bonding in the crystal structures of compounds Ph₂P(O)CH₂OH 21, Ph₂P(S)CH₂OH 22 and Ph₂P(Se)CH₂OH 23 was also investigated. Results were explained in terms of the positioning of hydrogen bonds in line with the direction of lone-pairs on the phosphine chalcogenide heteroatoms. 

The reaction of 1 with sodium metabisulfite in varying amounts was used to produce the compounds FcCH₂PH₂ 24, FcCH₂P(H)CH₂OH 25 and FcCH₂P(O)(OH)CH₂OH 26. The primary phosphine 24 was found to be remarkably air-stable, and was used to prepare the complexes Mo(CO)₅(FcCH₂PH₂) 27, Mo(CO)₄(FcCH₂PH₂)₂ 28, RuCl₂(η⁶-C₁₀H₁₄)(FcCH₂PH₂) 29, Ru₃(μ²-H)₂(CO)₉(μ³-PCH₂Fc) 30 and Ru₄(CO)₁₀(μ²-CO)(μ³-PCH₂Fc)₂ 31. Confirmation of the structures of 24, 27, 28 and 30 was obtained using X-ray crystallography. 

Cyclic voltammetric analysis of the electrochemical behaviour of 1, 2, 5, 24, 2S and FcCH(Me)P(CH₂OH)₂ 32 showed that these compounds exhibit a reversible one-electron oxidation followed by a chemical reaction, which leads to formation of a product which undergoes another reversible one-electron oxidation at higher potential. The rate-determining step for the reaction is intermolecular. BE (bulk electrolysis) of 1, 2 and 5 gave similar results in each case, with one-electron oxidation appearing to initially oxidise the ferrocene centre; in the case of 2 and 5 a green colour characteristic of ferrocenium species is seen during BE, but disappears with time. The conclusion was reached that this initial ferrocenium charge is transferred to another part of the molecule. Evidence from NMR and electrospray mass spectrometric analysis of BE products for 1 and 2 suggests the formation of unusual dimeric species is the end result of oxidation. The ferrocenylphosphine 11 shows simpler electrochemical behaviour consistent with previous literature. Compounds 3, 4, 8, 10, 14, 15, 16, 17, 18 and 30 showed very simple electrochemical behaviour consistent with one chemically and electrochemically reversible ferrocene redox couple. Cyclic voltammetry of the complexes 19, 20 and 29 showed both ferrocene and ruthenium redox processes. The electrochemistry of 7 was complex and not intensively investigated.  

Reaction of 1 with multi-functional secondary amines was used to produce a number of polymeric materials which were investigated using cyclic voltammetry of DMF solutions carbon paste electrodes and drop-coated electrodes. Attempts to covalently bind one of these, polymers to a glassy carbon electrode were unsuccessful. The most electrochemically stable form of electrode investigated was the carbon paste electrode, although the materials did not appear to show great promise for use in such applications, due to irreversible chemical changes in the polymers and quick decay of the ferrocene redox signal upon subjection to cyclic voltammetry.

text: A study of novel ferrocenyl-phosphorus compounds The intent of this investigation was to use the distinctive characteristics of hydroxymethylphosphine chemistry in order to create new ferrocenyl-phosphorus compounds, as well as carry out investigations into both their electrochemistry and their potential for the production of ferrocene-containing polymers. 

The compound FcCH₂P(CH₂OH)₂ 1 (Fe = ferrocenyl) was prepared by the reaction of P(CH₂OH)₃ with [FcCH₂NMe₃]I, and FcCH₂PPh₂ 2 was prepared by a similar reaction. The compounds FcCH₂P(O)(CH₂OH)₂ 3, FcCH₂P(S)(CH₂OH)₂ 4, FcCH₂P(CH₂CH₂CN)₂ 5, FcCH₂P(CH₂NEt₂)₂ 6, FcCH₂P(O)(CH₂Net₂)₂ 7, [FcCH₂P(Me)(CH₂OH)₂]I 8, FcCH₂P(Me)CH₂OH 9, [(FcCH₂)₂P(CH₂OH)₂]Cl 10, (FcCH₂)₂PCH₂OH 11, FcCH₂P(H)PPh₂ 14 and FcCH₂P(O)PPh₂ 15 were prepared and characterised, and the compounds [FcCH₂P(Bz)(CH₂OH)₂]Br (Bz = benzyl) 12 and FcCH₂P(Bz)CH₂OH 13 were investigated though not fully characterised. The ferrocenylphosphine complexes cis- PtCl₂[FcCH₂P(CH₂OH)₂]₂ 16, PdCl₂[FcCH₂P(CH₂OH)₂]₂ 17, [Au{FcCH₂P(CH₂OH)₂}₂]Cl 18, RuCl₂(η⁶-C₁₀H₁₄)[FcCH₂P(CH₂OH)₂] 19 and RuCl₂ (η⁶-C₁₀H₁₄)(FcCH₂PPh₂) 20 were also prepared. X-ray crystal structure determinations were carried out for the compounds 1, 2, 4, 8, 18 and 20, and the solid-state hydrogen-bonding interactions present in the case of 1, 4, 8 and 18 were deduced. 

Hydrogen-bonding in the crystal structures of compounds Ph₂P(O)CH₂OH 21, Ph₂P(S)CH₂OH 22 and Ph₂P(Se)CH₂OH 23 was also investigated. Results were explained in terms of the positioning of hydrogen bonds in line with the direction of lone-pairs on the phosphine chalcogenide heteroatoms. 

The reaction of 1 with sodium metabisulfite in varying amounts was used to produce the compounds FcCH₂PH₂ 24, FcCH₂P(H)CH₂OH 25 and FcCH₂P(O)(OH)CH₂OH 26. The primary phosphine 24 was found to be remarkably air-stable, and was used to prepare the complexes Mo(CO)₅(FcCH₂PH₂) 27, Mo(CO)₄(FcCH₂PH₂)₂ 28, RuCl₂(η⁶-C₁₀H₁₄)(FcCH₂PH₂) 29, Ru₃(μ²-H)₂(CO)₉(μ³-PCH₂Fc) 30 and Ru₄(CO)₁₀(μ²-CO)(μ³-PCH₂Fc)₂ 31. Confirmation of the structures of 24, 27, 28 and 30 was obtained using X-ray crystallography. 

Cyclic voltammetric analysis of the electrochemical behaviour of 1, 2, 5, 24, 2S and FcCH(Me)P(CH₂OH)₂ 32 showed that these compounds exhibit a reversible one-electron oxidation followed by a chemical reaction, which leads to formation of a product which undergoes another reversible one-electron oxidation at higher potential. The rate-determining step for the reaction is intermolecular. BE (bulk electrolysis) of 1, 2 and 5 gave similar results in each case, with one-electron oxidation appearing to initially oxidise the ferrocene centre; in the case of 2 and 5 a green colour characteristic of ferrocenium species is seen during BE, but disappears with time. The conclusion was reached that this initial ferrocenium charge is transferred to another part of the molecule. Evidence from NMR and electrospray mass spectrometric analysis of BE products for 1 and 2 suggests the formation of unusual dimeric species is the end result of oxidation. The ferrocenylphosphine 11 shows simpler electrochemical behaviour consistent with previous literature. Compounds 3, 4, 8, 10, 14, 15, 16, 17, 18 and 30 showed very simple electrochemical behaviour consistent with one chemically and electrochemically reversible ferrocene redox couple. Cyclic voltammetry of the complexes 19, 20 and 29 showed both ferrocene and ruthenium redox processes. The electrochemistry of 7 was complex and not intensively investigated.  

Reaction of 1 with multi-functional secondary amines was used to produce a number of polymeric materials which were investigated using cyclic voltammetry of DMF solutions carbon paste electrodes and drop-coated electrodes. Attempts to covalently bind one of these, polymers to a glassy carbon electrode were unsuccessful. The most electrochemically stable form of electrode investigated was the carbon paste electrode, although the materials did not appear to show great promise for use in such applications, due to irreversible chemical changes in the polymers and quick decay of the ferrocene redox signal upon subjection to cyclic voltammetry.

year: 1998

title: The Value of Irrigation Water in New Zealand

authors: Kravchenko, Alexey

subjects: irrigation

abstract: The aim of this thesis is to examine issues pertaining to freshwater quantity in New Zealand agriculture. Currently, freshwater is managed under the Resource Management Act (1991) and the allocation system is essentially on a “first-come first-served” basis – whoever gains access to water rights first blocks out subsequent users, if catchment allocation limits have been reached.   One of the recommendations from a government taskforce engaged to look at the issues of freshwater management suggests that market mechanisms or charges could be viable options of demand management. For any such market or price mechanism to work, it is imperative to know the value of irrigation water in New Zealand as well as to understand wider economic ramifications of establishing such mechanisms. Currently, there is relatively little research concerning these issues and this thesis aims to fill this research gap. The methodologies used include an econometric analysis of dairy farm panel data, a stated choice experiment of irrigation consent holders and a computable general equilibrium [CGE] analysis. In addition to filling the research gap, this thesis also aims to provide improvements in each of the methodologies used. Panel data analysis imputes the water demand function without actual data on water through examining the relationship between milksolid production and output-weighted expected payout – a unique dairy price index developed that more accurately reflects farmers’ incentives than the final payout. The choice modelling section pays particular attention to the issue of attribute non-attendance [ANA], eexamining  its effects on model outputs and compares methods of data collection on ANA. The main findings of the survey suggest that the majority of farmers would be willing to pay for water instead of facing an abstraction ban. In terms of ANA, the results indicate that not accounting for ANA, particularly if it is due to heuristics or respondent fatigue, may significantly bias the welfare estimates and decrease statistical significance. A novel calibration method is presented to negate the ANA bias. Finally, the CGE modelling work modifies the well-known GTAP model to include water as factor of production, as well as to disaggregate the results to a regional level within the New Zealand economy. The findings indicate strong interconnectedness between sectors and regions, with policies in one region having the potential to affect economic activity and resource demand in other regions.

text: The Value of Irrigation Water in New Zealand The aim of this thesis is to examine issues pertaining to freshwater quantity in New Zealand agriculture. Currently, freshwater is managed under the Resource Management Act (1991) and the allocation system is essentially on a “first-come first-served” basis – whoever gains access to water rights first blocks out subsequent users, if catchment allocation limits have been reached.   One of the recommendations from a government taskforce engaged to look at the issues of freshwater management suggests that market mechanisms or charges could be viable options of demand management. For any such market or price mechanism to work, it is imperative to know the value of irrigation water in New Zealand as well as to understand wider economic ramifications of establishing such mechanisms. Currently, there is relatively little research concerning these issues and this thesis aims to fill this research gap. The methodologies used include an econometric analysis of dairy farm panel data, a stated choice experiment of irrigation consent holders and a computable general equilibrium [CGE] analysis. In addition to filling the research gap, this thesis also aims to provide improvements in each of the methodologies used. Panel data analysis imputes the water demand function without actual data on water through examining the relationship between milksolid production and output-weighted expected payout – a unique dairy price index developed that more accurately reflects farmers’ incentives than the final payout. The choice modelling section pays particular attention to the issue of attribute non-attendance [ANA], eexamining  its effects on model outputs and compares methods of data collection on ANA. The main findings of the survey suggest that the majority of farmers would be willing to pay for water instead of facing an abstraction ban. In terms of ANA, the results indicate that not accounting for ANA, particularly if it is due to heuristics or respondent fatigue, may significantly bias the welfare estimates and decrease statistical significance. A novel calibration method is presented to negate the ANA bias. Finally, the CGE modelling work modifies the well-known GTAP model to include water as factor of production, as well as to disaggregate the results to a regional level within the New Zealand economy. The findings indicate strong interconnectedness between sectors and regions, with policies in one region having the potential to affect economic activity and resource demand in other regions.

year: 2016

title: Decolonising professional learning: Weaving a whānau of interest

authors: Pennicott, Katie

subjects: educational leadership

abstract: Raranga (weaving) has been described as an act of decolonisation and resistance. In my experience, learning to weave was more than an act of learning the tikanga (rituals) and methods with which to weave flax and tukutuku (lattice work); it was learning about learning and learning about living, life and all the things that make us who we are. As I experienced and began to understand Māori metaphors such as whanaungatanga, kaupapa, ako and manaakitanga I found that learning the art of weaving shaped me as I shaped the weaving. This thesis ideates a metaphor of weaving to describe a model of cultural and structural school reform that emerged from a school’s teaching and learning collaborations over time. It calls for the weaving of a new, decolonised model of education.

text: Decolonising professional learning: Weaving a whānau of interest Raranga (weaving) has been described as an act of decolonisation and resistance. In my experience, learning to weave was more than an act of learning the tikanga (rituals) and methods with which to weave flax and tukutuku (lattice work); it was learning about learning and learning about living, life and all the things that make us who we are. As I experienced and began to understand Māori metaphors such as whanaungatanga, kaupapa, ako and manaakitanga I found that learning the art of weaving shaped me as I shaped the weaving. This thesis ideates a metaphor of weaving to describe a model of cultural and structural school reform that emerged from a school’s teaching and learning collaborations over time. It calls for the weaving of a new, decolonised model of education.

year: 2020