title: E/Z isomerism in monoalkylated derivatives of [Pt₂(μ-S)₂(PPh₃)₄] containing 2,4-dinitrophenylhydrazone substituents

authors: Ujam, Oguejiofo Theophilus

subjects: Platinum complexes

abstract: Alkylation of [Pt₂(m-S)₂(PPh₃)₄] with 2,4-dinitrophenylhydrazone-functionalized alkylating agents XC6H4C{¼NNHC₆H₃(NO₂)₂}CH2Br (X¼H, Ph) gives monoalkylated cations [Pt₂(m-S){m-SCH₂C{¼NNHC₆H₃(NO₂)₂}C₆H₄X}(PPh₃)₄]⁺. An X-ray diffraction study on [Pt₂(m-S){m-SCH₂C{¼NNHC₆H₃(NO₂)₂}Ph}(PPh₃)₄]BPh₄ shows the crystal to be the Z isomer, with the phenyl ring and NHC₆H₃(NO₂)₂ groups mutually trans. ¹H- and ³¹P{¹H} NMR spectroscopic methods indicate a mixture of Z (major) and E (minor) isomers in solution, which slowly convert mainly to the E isomer. Reaction of [Pt₂(m-S)₂ (PPh₃)₄] with the dinitrophenylhydrazone of chloroacetone [ClCH₂C{¼NNH(C₆H₃(NO₂)₂}Me] and NaBPh₄ gives [Pt₂ (m-S){m-SCH₂C{¼NNHC₆H₃(NO₂)₂}Me}(PPh₃)₄]BPh₄, which exists as a single (E) isomer.

text: E/Z isomerism in monoalkylated derivatives of [Pt₂(μ-S)₂(PPh₃)₄] containing 2,4-dinitrophenylhydrazone substituents Alkylation of [Pt₂(m-S)₂(PPh₃)₄] with 2,4-dinitrophenylhydrazone-functionalized alkylating agents XC6H4C{¼NNHC₆H₃(NO₂)₂}CH2Br (X¼H, Ph) gives monoalkylated cations [Pt₂(m-S){m-SCH₂C{¼NNHC₆H₃(NO₂)₂}C₆H₄X}(PPh₃)₄]⁺. An X-ray diffraction study on [Pt₂(m-S){m-SCH₂C{¼NNHC₆H₃(NO₂)₂}Ph}(PPh₃)₄]BPh₄ shows the crystal to be the Z isomer, with the phenyl ring and NHC₆H₃(NO₂)₂ groups mutually trans. ¹H- and ³¹P{¹H} NMR spectroscopic methods indicate a mixture of Z (major) and E (minor) isomers in solution, which slowly convert mainly to the E isomer. Reaction of [Pt₂(m-S)₂ (PPh₃)₄] with the dinitrophenylhydrazone of chloroacetone [ClCH₂C{¼NNH(C₆H₃(NO₂)₂}Me] and NaBPh₄ gives [Pt₂ (m-S){m-SCH₂C{¼NNHC₆H₃(NO₂)₂}Me}(PPh₃)₄]BPh₄, which exists as a single (E) isomer.

year: 2011

title: Cellulolytic properties of an extremely thermophilic anaerobe

authors: Hudson, J. Andrew

subjects: biology

abstract: An extremely thermophilic anaerobe was isolated from a New Zealand hot spring by incubating bacterial mat strands in a medium containing xylan. The Gramreaction-negative organism that was subsequently purified had a temperature optimum of 70° C and a pH optimum of 7.0. The isolate, designated strain H173, grew on a restricted range of carbon sources. In batch culture H173 could degrade Avicel completely when supplied at 5 or 10 g l⁻¹. There was an initial growth phase, during which a cellulase complex was produced and carbohydrates fermented to form acetic and lactic acids, followed by a phase where cells were not metabolising but the cellulase complex actively converted cellulose to glucose. When co-cultured with strain Rt8.B1, an ethanologenic extreme thermophile, glucose was fermented to ethanol and acetate, and no reducing sugars accumulated in the medium. In pH controlled batch culture H173 produced an increased amount of lactate and acetate but there was again a phase when reducing sugars accumulated in the medium, and these were converted to ethanol by co-culture with Rt8.B1.

text: Cellulolytic properties of an extremely thermophilic anaerobe An extremely thermophilic anaerobe was isolated from a New Zealand hot spring by incubating bacterial mat strands in a medium containing xylan. The Gramreaction-negative organism that was subsequently purified had a temperature optimum of 70° C and a pH optimum of 7.0. The isolate, designated strain H173, grew on a restricted range of carbon sources. In batch culture H173 could degrade Avicel completely when supplied at 5 or 10 g l⁻¹. There was an initial growth phase, during which a cellulase complex was produced and carbohydrates fermented to form acetic and lactic acids, followed by a phase where cells were not metabolising but the cellulase complex actively converted cellulose to glucose. When co-cultured with strain Rt8.B1, an ethanologenic extreme thermophile, glucose was fermented to ethanol and acetate, and no reducing sugars accumulated in the medium. In pH controlled batch culture H173 produced an increased amount of lactate and acetate but there was again a phase when reducing sugars accumulated in the medium, and these were converted to ethanol by co-culture with Rt8.B1.

year: 1990

title: Disabled Māori and disability support options

authors: Nikora, Linda Waimarie

subjects: Maori

abstract: The goal of this research project was to provide information to enhance the development and implementation of an effective model of disability support service provision to Maori with disabilities. This was done by identifying and documenting the needs expressed by disabled Maori and their carers living in the Midland area, and by considering the experiences and observations of a key informant group. From our reading of the literature and the feedback we received from participants, a proposed model of disability support service provision has been proposed.

In five sections, this report begins by defining disability, and also by defining the act of caring for the disabled. Focussing on the Maori experience, obstacles, access to existing support services, cultural barriers, and health policies are discussed. In the second chapter, the research methodology is described, along with how the information was gathered. Following this is the third section which presents the opinions and reflections of Maori with disabilities. It concludes strategically with a view of the ideal community, suggesting possible resolutions, by exposing current flaws and inadequacies. Chapter four records the views and perspectives of key informant/whanau carers who participated in the project. They offer an insightful account of the often unrecognised side of the disability experience. Considering the preceding discussions, the final section develops a model of service provision for Maori with disabilities, and proposes this for effective service delivery.

text: Disabled Māori and disability support options The goal of this research project was to provide information to enhance the development and implementation of an effective model of disability support service provision to Maori with disabilities. This was done by identifying and documenting the needs expressed by disabled Maori and their carers living in the Midland area, and by considering the experiences and observations of a key informant group. From our reading of the literature and the feedback we received from participants, a proposed model of disability support service provision has been proposed.

In five sections, this report begins by defining disability, and also by defining the act of caring for the disabled. Focussing on the Maori experience, obstacles, access to existing support services, cultural barriers, and health policies are discussed. In the second chapter, the research methodology is described, along with how the information was gathered. Following this is the third section which presents the opinions and reflections of Maori with disabilities. It concludes strategically with a view of the ideal community, suggesting possible resolutions, by exposing current flaws and inadequacies. Chapter four records the views and perspectives of key informant/whanau carers who participated in the project. They offer an insightful account of the often unrecognised side of the disability experience. Considering the preceding discussions, the final section develops a model of service provision for Maori with disabilities, and proposes this for effective service delivery.

year: 2004-01-01