title: Stabilisation effects of ferrocenylalkyl groups on hydrides of heavier main group elements

authors: Asamizu, Toshie

subjects: heavier p-block main group element hydrides

abstract: New hydrides of heavier p-block main group elements with a ferrocenylalkyl moiety, Fc(CH₂)nEHm (Fc = (CpFeC₅H₄-); E = P, As, Si, Ge or Se; n = 1, 2, 4, 6 or 11; m = 1, 2 or 3) and FcCH₂P(R)H (R = CH₃, C₆H₁₁ or p-CH₂C₆H₄NO₂), have been synthesised and characterised. Although some precursors of the desired hydrides, i.e. Fc(Cl)C=C(SnCl₃)H and (FcCH₂Te)₂, which are also new compounds, could be prepared, the syntheses of the corresponding desired hydrides, FcCH₂EHn, were unsuccessful probably due to their extreme instabilities. Some related primary phosphanes, [CpFeC₅H₃(CH₂OH)(CH₂PH₂)], RcCH₂PH₂ and Fc(CH₂)₆PH₂∙BH₃, phosphane oxide, FcCH₂P(O)H₂, and phosphinic acid, FcCH₂P(O)(OH)H, were also synthesised and reported. The X-ray crystal structures of Fc(CH₂)₆PH₂∙BH3 and FcCH₂SeCN are also presented in the present thesis.
The stability of the hydrides of heavier p-block main group elements with a ferrocenyl or ruthenocenylalkyl moiety under ambient conditions has been investigated using NMR and/or IR spectroscopy. Ferrocenylalkyl and ruthenocenylmethyl primary phosphanes, Fc(CH₂)nPH₂ (n = 4, 6 or 11) and RcCH₂PH₂, respectively, exhibited a remarkable stability towards air oxidation in solution, i.e. ~1 year. In contrast, the secondary phosphanes were not as stable as expected, rapidly oxidising over several weeks or months. General trend for the oxidative stability of the secondary phosphanes could not be elucidated on the basis of the electronegativity, size or degree of conjugation of the substituent on the phosphorus. Ferrocenylmethyl primary arsane, FcCH₂AsH₂, was also unexpectedly air-sensitive, having been readily oxidised as a neat liquid or in solution upon the exposure to air.
Ferrocenylethyl primary silane, Fc(CH₂)₂SiH₃, was stable both as a neat liquid and also in solution. It could be purified on a TLC plate in air and also stored in solution for up to 7 months. On the other hand, ferrocenylmethyl primary germane, FcCH₂GeH₃, was unstable, almost completely decomposing left overnight in solution, which was indicated by the disappearance of the germane proton NMR signal by ¹H NMR spectroscopy.
Ferrocenylalkyl selenols, Fc(CH₂)nSeH (n = 1 or 4), were both found to be unstable as neat liquids or in solution. Handling the compounds in air caused significant oxidation, resulting in the formation of the corresponding diselenides which are the common oxidation products of selenols. Ferrocenylmethyl selenol, FcCH₂SeH, was completely oxidised in solution in air in 5 days while ferrocenylbutyl selenol, Fc(CH₂)₄SeH, in 3 days. The rapid oxidation of the latter was also observed by IR spectroscopy over a period of 10 minutes when exposed to air as a neat liquid.
The oxidative stability of the air-sensitive primary phosphanes, PhPH₂ and camphylPH₂, in the presence of ferrocene, FcH, or its derivative, FcCH₂PH₂, in solution, was studied by ³¹P NMR spectroscopy. The study showed that the primary phosphanes could be stabilised by simple addition of FcH or FcCH₂PH₂. The corresponding ³¹P NMR study using known antioxidants, diphenyl picryl hydrazyl (DPPH) or nitrosobutane, in place of the ferrocene species also exhibited that PhPH₂ could be stabilised by addition of an antioxidant. These results suggest that FcH and FcCH₂PH₂ can be used to stabilise air-sensitive primary phosphanes in solution by simply adding them, probably acting as radical scavengers.

text: Stabilisation effects of ferrocenylalkyl groups on hydrides of heavier main group elements New hydrides of heavier p-block main group elements with a ferrocenylalkyl moiety, Fc(CH₂)nEHm (Fc = (CpFeC₅H₄-); E = P, As, Si, Ge or Se; n = 1, 2, 4, 6 or 11; m = 1, 2 or 3) and FcCH₂P(R)H (R = CH₃, C₆H₁₁ or p-CH₂C₆H₄NO₂), have been synthesised and characterised. Although some precursors of the desired hydrides, i.e. Fc(Cl)C=C(SnCl₃)H and (FcCH₂Te)₂, which are also new compounds, could be prepared, the syntheses of the corresponding desired hydrides, FcCH₂EHn, were unsuccessful probably due to their extreme instabilities. Some related primary phosphanes, [CpFeC₅H₃(CH₂OH)(CH₂PH₂)], RcCH₂PH₂ and Fc(CH₂)₆PH₂∙BH₃, phosphane oxide, FcCH₂P(O)H₂, and phosphinic acid, FcCH₂P(O)(OH)H, were also synthesised and reported. The X-ray crystal structures of Fc(CH₂)₆PH₂∙BH3 and FcCH₂SeCN are also presented in the present thesis.
The stability of the hydrides of heavier p-block main group elements with a ferrocenyl or ruthenocenylalkyl moiety under ambient conditions has been investigated using NMR and/or IR spectroscopy. Ferrocenylalkyl and ruthenocenylmethyl primary phosphanes, Fc(CH₂)nPH₂ (n = 4, 6 or 11) and RcCH₂PH₂, respectively, exhibited a remarkable stability towards air oxidation in solution, i.e. ~1 year. In contrast, the secondary phosphanes were not as stable as expected, rapidly oxidising over several weeks or months. General trend for the oxidative stability of the secondary phosphanes could not be elucidated on the basis of the electronegativity, size or degree of conjugation of the substituent on the phosphorus. Ferrocenylmethyl primary arsane, FcCH₂AsH₂, was also unexpectedly air-sensitive, having been readily oxidised as a neat liquid or in solution upon the exposure to air.
Ferrocenylethyl primary silane, Fc(CH₂)₂SiH₃, was stable both as a neat liquid and also in solution. It could be purified on a TLC plate in air and also stored in solution for up to 7 months. On the other hand, ferrocenylmethyl primary germane, FcCH₂GeH₃, was unstable, almost completely decomposing left overnight in solution, which was indicated by the disappearance of the germane proton NMR signal by ¹H NMR spectroscopy.
Ferrocenylalkyl selenols, Fc(CH₂)nSeH (n = 1 or 4), were both found to be unstable as neat liquids or in solution. Handling the compounds in air caused significant oxidation, resulting in the formation of the corresponding diselenides which are the common oxidation products of selenols. Ferrocenylmethyl selenol, FcCH₂SeH, was completely oxidised in solution in air in 5 days while ferrocenylbutyl selenol, Fc(CH₂)₄SeH, in 3 days. The rapid oxidation of the latter was also observed by IR spectroscopy over a period of 10 minutes when exposed to air as a neat liquid.
The oxidative stability of the air-sensitive primary phosphanes, PhPH₂ and camphylPH₂, in the presence of ferrocene, FcH, or its derivative, FcCH₂PH₂, in solution, was studied by ³¹P NMR spectroscopy. The study showed that the primary phosphanes could be stabilised by simple addition of FcH or FcCH₂PH₂. The corresponding ³¹P NMR study using known antioxidants, diphenyl picryl hydrazyl (DPPH) or nitrosobutane, in place of the ferrocene species also exhibited that PhPH₂ could be stabilised by addition of an antioxidant. These results suggest that FcH and FcCH₂PH₂ can be used to stabilise air-sensitive primary phosphanes in solution by simply adding them, probably acting as radical scavengers.

year: 2013

title: Predicting the effects of climate change on trophic status of three morphologically varying lakes: Implications for lake restoration and management

authors: Trolle, Dennis

subjects: DYRESM-CAEDYM

abstract: To quantify the effects of a future climate on three morphologically different lakes that varied in trophic status from oligo-mesotrophic to highly eutrophic, we applied the one-dimensional lake ecosystem model DYRESM-CAEDYM to oligo-mesotrophic Lake Okareka, eutrophic Lake Rotoehu, both in the temperate Bay of Plenty region, and highly eutrophic Lake Ellesmere, in the temperate Canterbury region, New Zealand. All three models were calibrated for a three-year period and validated for a separate two-year period. The model simulations generally showed good agreement with observed data for water column temperature, dissolved oxygen (DO), total phosphorus (TP), total nitrogen (TN) and chlorophyll a (Chl a) concentrations. To represent a possible future climate at the end of this century, mean annual changes in air temperature by 2100, derived from the IPCC A2 scenario downscaled for these lake regions, were added to the daily baseline temperatures for years 2002–2007. Lake model simulations using this future climate scenario indicate differential increases in eutrophication in all three lakes, especially during summer months. The predicted effects on annual mean surface water concentrations of TP, TN and Chl a will be equivalent to the effects of increasing external TN and TP loading by 25–50%. Simulations for the polymictic, eutrophic Lake Rotoehu further indicate that cyanophytes will be more abundant in the future climate, increasing by >15% in their contribution to annual mean Chl a. Therefore, future climate effects should be taken into account in the long-term planning and implementation of lake management as strategies may need to be refined and adapted to preserve or improve the present-day lake water quality.

text: Predicting the effects of climate change on trophic status of three morphologically varying lakes: Implications for lake restoration and management To quantify the effects of a future climate on three morphologically different lakes that varied in trophic status from oligo-mesotrophic to highly eutrophic, we applied the one-dimensional lake ecosystem model DYRESM-CAEDYM to oligo-mesotrophic Lake Okareka, eutrophic Lake Rotoehu, both in the temperate Bay of Plenty region, and highly eutrophic Lake Ellesmere, in the temperate Canterbury region, New Zealand. All three models were calibrated for a three-year period and validated for a separate two-year period. The model simulations generally showed good agreement with observed data for water column temperature, dissolved oxygen (DO), total phosphorus (TP), total nitrogen (TN) and chlorophyll a (Chl a) concentrations. To represent a possible future climate at the end of this century, mean annual changes in air temperature by 2100, derived from the IPCC A2 scenario downscaled for these lake regions, were added to the daily baseline temperatures for years 2002–2007. Lake model simulations using this future climate scenario indicate differential increases in eutrophication in all three lakes, especially during summer months. The predicted effects on annual mean surface water concentrations of TP, TN and Chl a will be equivalent to the effects of increasing external TN and TP loading by 25–50%. Simulations for the polymictic, eutrophic Lake Rotoehu further indicate that cyanophytes will be more abundant in the future climate, increasing by >15% in their contribution to annual mean Chl a. Therefore, future climate effects should be taken into account in the long-term planning and implementation of lake management as strategies may need to be refined and adapted to preserve or improve the present-day lake water quality.

year: 2010

title: Shifting tectonic plates of key discourses in New Zealand early childhood education policy (1989-2017):  A critical discourse analysis at the dawn of change

authors: Westbrook, Fiona

subjects: New Zealand

abstract: This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
The findings of this thesis imply socialism, te Ao Māori and neoliberalism are constantly competing with one another in the analysed policies that construct New Zealand ECE discourses and, as a consequence, influence practice. This plurality has the potential to hinder one discourse from gaining domination over the others. Their joint consumption's and conflicts appear to periodically lessen and strengthen neoliberalism’s power/knowledges across eras, administrations, policies and paragraphs, as exemplified in the updated curriculum. These findings imply that the ‘drivers’ of power are pivotal, hindering and strengthening these discourses which are both complementary and competing. Additionally, the thesis establishes implications regarding the rich complexities of discourses, which can conceal themselves in other discourses, calling for deeper critical reflection if some power/knowledges are to be reduced.

text: Shifting tectonic plates of key discourses in New Zealand early childhood education policy (1989-2017):  A critical discourse analysis at the dawn of change This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
The findings of this thesis imply socialism, te Ao Māori and neoliberalism are constantly competing with one another in the analysed policies that construct New Zealand ECE discourses and, as a consequence, influence practice. This plurality has the potential to hinder one discourse from gaining domination over the others. Their joint consumption's and conflicts appear to periodically lessen and strengthen neoliberalism’s power/knowledges across eras, administrations, policies and paragraphs, as exemplified in the updated curriculum. These findings imply that the ‘drivers’ of power are pivotal, hindering and strengthening these discourses which are both complementary and competing. Additionally, the thesis establishes implications regarding the rich complexities of discourses, which can conceal themselves in other discourses, calling for deeper critical reflection if some power/knowledges are to be reduced.

year: 2018