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: Zooplankton Dynamics in Wastewater Treatment High Rate Algal Ponds and development of effective control methods

authors: Montemezzani, Valerio

subjects: Wastewater treatment High Rate Algal Pond

abstract: High Rate Algal Ponds (HRAPs) are effective and economical open pond to provide near tertiary-level wastewater (WW) treatment, with the nutrients recovered as algal biomass. However, WW treatment performance can be reduced by the establishment of zooplankton grazers which can consume much of the algal biomass within a few days. The high food availability and the near neutral pH in HRAPs offer optimal conditions for the establishment of zooplankton taxa including cladocerans and rotifers. The control of these zooplankton species is essential for the effective operation of HRAPs. This thesis research was aimed at designing cost-effective treatments to control zooplankton population densities applicable to full-scale HRAPs. In this thesis, I: 1) reviewed existing and potential methods for zooplankton control in HRAPs; 2) assessed environmental and biological parameters for two wastewater HRAPs with CO₂ addition using a 14 month large-scale field experiment; 3) assessed chemical CO₂ asphyxiation, biological control of rotifers using competitor species, mechanical disruption of zooplankton using hydrodynamic shear stress, and the mechanical removal of zooplankton using filtration, using controlled laboratory conditions; 4) validated chronic CO₂ asphyxiation of zooplankton, the biocontrol of rotifers using the cladoceran M. tenuicornis and the ostracod H. incongruens, the control of M. tenuicornis using filtration and the hydrodynamic disruption of zooplankton, using outdoor mesocosms with physicochemical and operational conditions similar to those of full scale HRAPs; 5) assessed night time CO₂ asphyxiation to control zooplankton densities in an 8 m³ HRAP over 14 months.
During the 14 months of the field experiment, zooplankton dynamics in paired 8 m³ HRAPs eight species of zooplankton established, with higher water temperatures and longer detention times promoting larger populations. Grazing pressure was associated with changes in the dominance of microalgal species; large and rapid reductions of productivity; reduced nutrient removal; increased colony size, number of cells in colonies and formation of protective spines in microalgae; and higher biomass settleability. Maintaining a dominance of colonial microalgae, operating HRAPs with short retention times, and facilitating competition among zooplankton species showed to potentially reduce grazer populations. Promising options for zooplankton control included physical methods such as filtration, hydrodynamic cavitation, shear, bead mills; chemical methods such as increase of HRAP night-time CO₂ concentration, promotion of the lethal un-ionized ammonia toxicity, use of biocides, and the chitinase inhibitor chitosan; biocontrol using competitor and predatory organisms. In the laboratory tests CO₂ asphyxiation caused acute mortality of all zooplankton species (t<10 min). Increasing the cladoceran Moina tenuicornis to densities >2,500 individuals/L was associated with a decrease in rotifer populations that were ~23% of the population in the control. The ostracod Heterocypris incongruens at densities >1,000 individuals/L were also associated with a decrease in rotifer densities that were ~27% of the population in the control. Hydrodynamic shear stress killed 100% of M. tenuicornis and ~80% of the rotifer Brachionus calyciflorus after a single pass. In outdoor mesocosms a continuous CO₂ concentration of ~100 mg/L maintained low pond water zooplankton densities, while a continuous concentration of ~180 mg/L killed all microcrustaceans and rotifers present. As biocontrol agents, M. tenuicornis at ~2,000 individuals/L reduced average rotifer densities by 90%, and H. incongruens at ~1,000 individuals/L removed all rotifers. Mechanical filtration using 300 µm and 500 µm filters eradicated M. tenuicornis after one and four filtration periods, respectively. Mechanical hydrodynamic stress killed up to 100% of microcrustaceans, and ~50% of larger rotifers. Zooplankton control using night time CO₂ asphyxiation in an 8 m³ HRAP reduced the average population densities of some zooplankton species over the experimental period: M. tenuicornis (41.3%), the copepod Paracyclops fimbriatus (43.9%), the rotifer Filinia longiseta (59.8%), but was associated with higher average population densities of others: H. incongruens (174.4%), the rotifers Asplanchna sieboldi (177.8%), Cephalodella catellina (200.0%), and B. calyciflorus (234.9%). However, the population densities of B. calyciflorus and C. catellina were always reduced after CO₂ treatments with flow rates ≥2 L/min were applied. The cladoceran Daphnia thomsoni and the rotifer Brachionus urceolaris established only in the control HRAP. Zooplankton control by CO₂ asphyxiation improved the overall performance of the treated WW HRAP compared to the control in several ways, including increasing algal biomass (VSS) (150.8%), productivity (151.4%), chlorophyll-a concentration (161.8%), particle size (MCSA) (115.8%), and average settleability efficiency (189.2%). Furthermore, M. tenuicornis was concentrated in the upper 50 mm of a 300 mm deep water column using vertical migration induced by CO₂ concentrations of between 25-180 mg/L in laboratory experiments, and by phototaxis-induced migration in an 8 m³ HRAP. This suggested that mechanical treatments such as filtration and hydrodynamic stress could be performed to the upper layer of the pond water, reducing the amount of water processed and the overall treatment costs. Overall, CO₂ asphyxiation appeared to be the most reliable, versatile, and effective zooplankton control treatment. 
All treatments reduced or eradicated zooplankton populations and promoted higher productivity of microalgae cultures. However, the efficacy of treatments to control diverse zooplankton species differed, and the implementation of any control strategy in a given system requires a preliminary assessment of zooplankton succession to identify the species able to consume the dominant microalgae that could establish in the system. Treatments can be dosed and combined to selectively kill specific zooplankton species. Moreover, zooplankton at controlled densities could potentially be used as a bio tool to improve biomass settleability or to consume unwanted microalgal species.

text: Zooplankton Dynamics in Wastewater Treatment High Rate Algal Ponds and development of effective control methods High Rate Algal Ponds (HRAPs) are effective and economical open pond to provide near tertiary-level wastewater (WW) treatment, with the nutrients recovered as algal biomass. However, WW treatment performance can be reduced by the establishment of zooplankton grazers which can consume much of the algal biomass within a few days. The high food availability and the near neutral pH in HRAPs offer optimal conditions for the establishment of zooplankton taxa including cladocerans and rotifers. The control of these zooplankton species is essential for the effective operation of HRAPs. This thesis research was aimed at designing cost-effective treatments to control zooplankton population densities applicable to full-scale HRAPs. In this thesis, I: 1) reviewed existing and potential methods for zooplankton control in HRAPs; 2) assessed environmental and biological parameters for two wastewater HRAPs with CO₂ addition using a 14 month large-scale field experiment; 3) assessed chemical CO₂ asphyxiation, biological control of rotifers using competitor species, mechanical disruption of zooplankton using hydrodynamic shear stress, and the mechanical removal of zooplankton using filtration, using controlled laboratory conditions; 4) validated chronic CO₂ asphyxiation of zooplankton, the biocontrol of rotifers using the cladoceran M. tenuicornis and the ostracod H. incongruens, the control of M. tenuicornis using filtration and the hydrodynamic disruption of zooplankton, using outdoor mesocosms with physicochemical and operational conditions similar to those of full scale HRAPs; 5) assessed night time CO₂ asphyxiation to control zooplankton densities in an 8 m³ HRAP over 14 months.
During the 14 months of the field experiment, zooplankton dynamics in paired 8 m³ HRAPs eight species of zooplankton established, with higher water temperatures and longer detention times promoting larger populations. Grazing pressure was associated with changes in the dominance of microalgal species; large and rapid reductions of productivity; reduced nutrient removal; increased colony size, number of cells in colonies and formation of protective spines in microalgae; and higher biomass settleability. Maintaining a dominance of colonial microalgae, operating HRAPs with short retention times, and facilitating competition among zooplankton species showed to potentially reduce grazer populations. Promising options for zooplankton control included physical methods such as filtration, hydrodynamic cavitation, shear, bead mills; chemical methods such as increase of HRAP night-time CO₂ concentration, promotion of the lethal un-ionized ammonia toxicity, use of biocides, and the chitinase inhibitor chitosan; biocontrol using competitor and predatory organisms. In the laboratory tests CO₂ asphyxiation caused acute mortality of all zooplankton species (t<10 min). Increasing the cladoceran Moina tenuicornis to densities >2,500 individuals/L was associated with a decrease in rotifer populations that were ~23% of the population in the control. The ostracod Heterocypris incongruens at densities >1,000 individuals/L were also associated with a decrease in rotifer densities that were ~27% of the population in the control. Hydrodynamic shear stress killed 100% of M. tenuicornis and ~80% of the rotifer Brachionus calyciflorus after a single pass. In outdoor mesocosms a continuous CO₂ concentration of ~100 mg/L maintained low pond water zooplankton densities, while a continuous concentration of ~180 mg/L killed all microcrustaceans and rotifers present. As biocontrol agents, M. tenuicornis at ~2,000 individuals/L reduced average rotifer densities by 90%, and H. incongruens at ~1,000 individuals/L removed all rotifers. Mechanical filtration using 300 µm and 500 µm filters eradicated M. tenuicornis after one and four filtration periods, respectively. Mechanical hydrodynamic stress killed up to 100% of microcrustaceans, and ~50% of larger rotifers. Zooplankton control using night time CO₂ asphyxiation in an 8 m³ HRAP reduced the average population densities of some zooplankton species over the experimental period: M. tenuicornis (41.3%), the copepod Paracyclops fimbriatus (43.9%), the rotifer Filinia longiseta (59.8%), but was associated with higher average population densities of others: H. incongruens (174.4%), the rotifers Asplanchna sieboldi (177.8%), Cephalodella catellina (200.0%), and B. calyciflorus (234.9%). However, the population densities of B. calyciflorus and C. catellina were always reduced after CO₂ treatments with flow rates ≥2 L/min were applied. The cladoceran Daphnia thomsoni and the rotifer Brachionus urceolaris established only in the control HRAP. Zooplankton control by CO₂ asphyxiation improved the overall performance of the treated WW HRAP compared to the control in several ways, including increasing algal biomass (VSS) (150.8%), productivity (151.4%), chlorophyll-a concentration (161.8%), particle size (MCSA) (115.8%), and average settleability efficiency (189.2%). Furthermore, M. tenuicornis was concentrated in the upper 50 mm of a 300 mm deep water column using vertical migration induced by CO₂ concentrations of between 25-180 mg/L in laboratory experiments, and by phototaxis-induced migration in an 8 m³ HRAP. This suggested that mechanical treatments such as filtration and hydrodynamic stress could be performed to the upper layer of the pond water, reducing the amount of water processed and the overall treatment costs. Overall, CO₂ asphyxiation appeared to be the most reliable, versatile, and effective zooplankton control treatment. 
All treatments reduced or eradicated zooplankton populations and promoted higher productivity of microalgae cultures. However, the efficacy of treatments to control diverse zooplankton species differed, and the implementation of any control strategy in a given system requires a preliminary assessment of zooplankton succession to identify the species able to consume the dominant microalgae that could establish in the system. Treatments can be dosed and combined to selectively kill specific zooplankton species. Moreover, zooplankton at controlled densities could potentially be used as a bio tool to improve biomass settleability or to consume unwanted microalgal species.

year: 2017

title: Te whakaihonga: He tikanga tapahi makawe i te ao Māori

authors: McDonald, Rangihurihia Ann

subjects: Tapahi makawe

abstract: E ai ki te Māori, mai anō i a Māui Pōtiki, kua tapahia e te pouaru, e te kirimate, ngō rātou makawe i te tangihanga. He reureu, he tiotio, he pakipaki taha ngētehi o ngā tohu weriweri nei, i tauawhi, i whakaū i te aroha ki te mate. I ngētehi wā, he whakamaumahara, he take whakariri i te ngākau, he utu i te tangi kino o te manawa. Mutu kau ana te tangihanga, ko te heuenga hoki i te whare tauā, ki te wai whakaika. Ko ngētehi take ngēnei o te tapahi makawe a te kirimate, otirā, ko te tino whāinga o tēnei tuhinga whakapae. He whakapono makawe anō i whakaemingia, nā te rangahau mātātuhi, ko ngā pūrākau, ngā mōteatea, ngā whakataukī anō hoki a ngā tūpuna. He tirohanga kaumātua i kohikohingia nā roto mai o te uiui. Waiho mai ana ko ngā tikanga tawhito mō te tapahi i te uru tapu o te tangata, ki te ao tūroa.

text: Te whakaihonga: He tikanga tapahi makawe i te ao Māori E ai ki te Māori, mai anō i a Māui Pōtiki, kua tapahia e te pouaru, e te kirimate, ngō rātou makawe i te tangihanga. He reureu, he tiotio, he pakipaki taha ngētehi o ngā tohu weriweri nei, i tauawhi, i whakaū i te aroha ki te mate. I ngētehi wā, he whakamaumahara, he take whakariri i te ngākau, he utu i te tangi kino o te manawa. Mutu kau ana te tangihanga, ko te heuenga hoki i te whare tauā, ki te wai whakaika. Ko ngētehi take ngēnei o te tapahi makawe a te kirimate, otirā, ko te tino whāinga o tēnei tuhinga whakapae. He whakapono makawe anō i whakaemingia, nā te rangahau mātātuhi, ko ngā pūrākau, ngā mōteatea, ngā whakataukī anō hoki a ngā tūpuna. He tirohanga kaumātua i kohikohingia nā roto mai o te uiui. Waiho mai ana ko ngā tikanga tawhito mō te tapahi i te uru tapu o te tangata, ki te ao tūroa.

year: 2011