title: Further investigations on the methylation chemistry of [Pt₂(μ-S)₂(PPh₃)₄]

authors: Henderson, William

subjects: Platinum complexes

abstract: The methylation product of the reaction between [Pt₂(µ-S)₂(PPh₃)₄] and MeI in diethyl ether has been reinvestigated using positive-ion electrospray mass spectrometry and found to be contaminated with the dimethylated iodide-containing complex [Pt₂(µ-SMe)₂(PPh₃)₃I]⁺, which is believed to be formed early in the reaction. New, facile routes to the monomethylated complex [Pt₂(µ-S)(µ-SMe)(PPh₃)₄]⁺ have been developed using mild methylating agents. Heating [Pt₂(µ-S)₂(PPh₃)₄] in neat dimethyl methylphosphonate results in rapid and selective conversion to [Pt₂(µ-S)(µ-SMe)(PPh₃)₄]⁺; methylation with Me₃S⁺OH⁻ in refluxing methanol also affords pure [Pt₂(µ-S)(µ-SMe)(PPh₃)₄]⁺, isolated as its hexafluorophosphate salt. The X-ray structure of the previously reported complex [Pt₂(µ-SMe)₂(PPh₃)₂I₂] has also been undertaken.

text: Further investigations on the methylation chemistry of [Pt₂(μ-S)₂(PPh₃)₄] The methylation product of the reaction between [Pt₂(µ-S)₂(PPh₃)₄] and MeI in diethyl ether has been reinvestigated using positive-ion electrospray mass spectrometry and found to be contaminated with the dimethylated iodide-containing complex [Pt₂(µ-SMe)₂(PPh₃)₃I]⁺, which is believed to be formed early in the reaction. New, facile routes to the monomethylated complex [Pt₂(µ-S)(µ-SMe)(PPh₃)₄]⁺ have been developed using mild methylating agents. Heating [Pt₂(µ-S)₂(PPh₃)₄] in neat dimethyl methylphosphonate results in rapid and selective conversion to [Pt₂(µ-S)(µ-SMe)(PPh₃)₄]⁺; methylation with Me₃S⁺OH⁻ in refluxing methanol also affords pure [Pt₂(µ-S)(µ-SMe)(PPh₃)₄]⁺, isolated as its hexafluorophosphate salt. The X-ray structure of the previously reported complex [Pt₂(µ-SMe)₂(PPh₃)₂I₂] has also been undertaken.

year: 2011

title: Cadmium mobilisation by dissolved organic matter in contaminated soils amended with compost and peat

authors: Welikala, Dharshika

abstract: Some organic matter (OM) soil amendments derived from biowaste have been shown to reduce plant uptake of Cd, which presents them as an attractive option for mitigating potential health risks on some contaminated soils. However, recent studies have highlighted that dissolved organic matter (DOM) release from the amendments may increase the mobilization of metals in those soils. The provenance of the OM and the quality of the emergent DOM have been suggested as important determinants in the extent to which this occurs. However, these effects have not been systematically tested in different soil environments, where the amount of DOM released from the OM, and its affinity to form Cd-DOM complexes, may vary. Our aim in this work was to explore whether the type of OM soil amendment influences Cd mobility in contaminated soils at different pHs, and if DOM characteristics contribute
to this effect.

text: Cadmium mobilisation by dissolved organic matter in contaminated soils amended with compost and peat Some organic matter (OM) soil amendments derived from biowaste have been shown to reduce plant uptake of Cd, which presents them as an attractive option for mitigating potential health risks on some contaminated soils. However, recent studies have highlighted that dissolved organic matter (DOM) release from the amendments may increase the mobilization of metals in those soils. The provenance of the OM and the quality of the emergent DOM have been suggested as important determinants in the extent to which this occurs. However, these effects have not been systematically tested in different soil environments, where the amount of DOM released from the OM, and its affinity to form Cd-DOM complexes, may vary. Our aim in this work was to explore whether the type of OM soil amendment influences Cd mobility in contaminated soils at different pHs, and if DOM characteristics contribute
to this effect.

year: 2019

title: Differential trends in the compression of mortality: Assessing the antecedents to current gaps in health expectancy in New Zealand

authors: Pool, Ian

subjects: New Zealand

abstract: Health Expectancies (HEs) for New Zealand show significant differentials between Maori and non-Maori, but also by gender and period. These differentials correlate with findings from both generation and synthetic life-tables relating to New Zealand’s epidemiologic transition. At the beginning of that transition quartile 1 (Q(1)), and Median (Med) d(x) values were close and centred at young ages; during the transition the gap became very wide; at the transition’s end the gap again narrowed. Cohort and synthetic trends in d(x), l(x), M, Qs and Meds are reviewed and linked to recent HEs. Data point to epidemic polarisation. Cohort analysis allows the evaluation of the role of past experiences on the recent HEs, and thus point to possible strategies for reducing gaps in both d(x), and HEs.

text: Differential trends in the compression of mortality: Assessing the antecedents to current gaps in health expectancy in New Zealand Health Expectancies (HEs) for New Zealand show significant differentials between Maori and non-Maori, but also by gender and period. These differentials correlate with findings from both generation and synthetic life-tables relating to New Zealand’s epidemiologic transition. At the beginning of that transition quartile 1 (Q(1)), and Median (Med) d(x) values were close and centred at young ages; during the transition the gap became very wide; at the transition’s end the gap again narrowed. Cohort and synthetic trends in d(x), l(x), M, Qs and Meds are reviewed and linked to recent HEs. Data point to epidemic polarisation. Cohort analysis allows the evaluation of the role of past experiences on the recent HEs, and thus point to possible strategies for reducing gaps in both d(x), and HEs.

year: 2009