title: Cluster Chemistry : XVII.Radical ion-initiated synthesis of ruthenium cluster carbonyls containing tertiary phosphines, phosphites, arsines, SbPh₃, or isocyanides

authors: Bruce, Michael I.

subjects: chemistry

abstract: The syntheses of over sixty known and new derivatives of Ru₃(CO)₁₂ and H₄Ru₄(CO)₁₂ by substitution reactions initiated by sodium diphenylketyl are described. The range of ligands studied includes isocyanides, tertiary phosphines and phosphites, tertiary arsines and SbPh₃. The reactions are characterised by high degrees of specificity and conversion: under mild conditions up to four ligands can be introduced. Comparisons with the corresponding thermally induced reactions are made in several cases. The reactions provide routes to mixed ligand derivatives of the cluster carbonyls, although account of relative Lewis base strengths of the ligands may have to be taken. Possible mechanisms of these reactions are discussed briefly, as are the IR ν (CO) spectra of the Ru₃ (CO)12-nLn complexes.

text: Cluster Chemistry : XVII.Radical ion-initiated synthesis of ruthenium cluster carbonyls containing tertiary phosphines, phosphites, arsines, SbPh₃, or isocyanides The syntheses of over sixty known and new derivatives of Ru₃(CO)₁₂ and H₄Ru₄(CO)₁₂ by substitution reactions initiated by sodium diphenylketyl are described. The range of ligands studied includes isocyanides, tertiary phosphines and phosphites, tertiary arsines and SbPh₃. The reactions are characterised by high degrees of specificity and conversion: under mild conditions up to four ligands can be introduced. Comparisons with the corresponding thermally induced reactions are made in several cases. The reactions provide routes to mixed ligand derivatives of the cluster carbonyls, although account of relative Lewis base strengths of the ligands may have to be taken. Possible mechanisms of these reactions are discussed briefly, as are the IR ν (CO) spectra of the Ru₃ (CO)12-nLn complexes.

year: 1983

title: Towards a radiocarbon calibration for oxygen isotope stage 3 using New Zealand kauri (Agathis australis)

authors: Turney, Chris S.M.

subjects: New Zealand kauri

abstract: It is well known that radiocarbon years do not directly equate to calendar time. As a result, considerable effort has been devoted to generating a decadally resolved calibration curve for the Holocene and latter part of the last termination. A calibration curve that can be unambiguously attributed to changes in atmospheric ¹⁴C content has not, however, been generated beyond 26 kyr cal BP, despite the urgent need to rigorously test climatic, environmental, and archaeological models. Here, we discuss the potential of New Zealand kauri (Agathis australis) to define the structure of the ¹⁴C calibration curve using annually resolved tree rings and thereby provide an absolute measure of atmospheric ¹⁴C. We report bidecadally sampled ¹⁴C measurements obtained from a floating 1050-yr chronology, demonstrating repeatable ¹⁴C measurements near the present limits of the dating method. The results indicate that considerable scope exists for a high-resolution ¹⁴C calibration curve back through OIS-3 using subfossil wood from this source.

text: Towards a radiocarbon calibration for oxygen isotope stage 3 using New Zealand kauri (Agathis australis) It is well known that radiocarbon years do not directly equate to calendar time. As a result, considerable effort has been devoted to generating a decadally resolved calibration curve for the Holocene and latter part of the last termination. A calibration curve that can be unambiguously attributed to changes in atmospheric ¹⁴C content has not, however, been generated beyond 26 kyr cal BP, despite the urgent need to rigorously test climatic, environmental, and archaeological models. Here, we discuss the potential of New Zealand kauri (Agathis australis) to define the structure of the ¹⁴C calibration curve using annually resolved tree rings and thereby provide an absolute measure of atmospheric ¹⁴C. We report bidecadally sampled ¹⁴C measurements obtained from a floating 1050-yr chronology, demonstrating repeatable ¹⁴C measurements near the present limits of the dating method. The results indicate that considerable scope exists for a high-resolution ¹⁴C calibration curve back through OIS-3 using subfossil wood from this source.

year: 2007

title: Using the stars to indigenize the public sphere: Matariki over New Zealand

authors: Hardy, Anna

subjects: Arts & Humanities

abstract: As the rate of affiliation to Christian identity continues to decline in Aotearoa New Zealand (only 49 percent of the population said they were Christian in the last census), public space has become more receptive to other forms of religiosity. In particular, community rituals around the winter movements of the Matariki (Pleiades) constellation have gained support since the year 2000. For instance, the capital city, Wellington, has replaced a centuries’ old British fireworks festival, Guy Fawkes, with an enlarged version of its Matariki celebrations: an action seen as a tipping point in the incorporation of Māori spiritual values into public life. Interactions between European colonisers and Māori have been characterised for more than 250 years by tensions between the relational thinking of Māori who see human beings as both participating in and constrained by an environment resonant with divine energies, and the quantitative, hierarchical, ‘Great Chain of Being’ model that had long been dominant among Europeans. Now, when the natural environment worldwide is under strain from population and economic pressures, it seems to some both appropriate and vital to look to epistemological and spiritual models that are intimately responsive to the specificities of location.

text: Using the stars to indigenize the public sphere: Matariki over New Zealand As the rate of affiliation to Christian identity continues to decline in Aotearoa New Zealand (only 49 percent of the population said they were Christian in the last census), public space has become more receptive to other forms of religiosity. In particular, community rituals around the winter movements of the Matariki (Pleiades) constellation have gained support since the year 2000. For instance, the capital city, Wellington, has replaced a centuries’ old British fireworks festival, Guy Fawkes, with an enlarged version of its Matariki celebrations: an action seen as a tipping point in the incorporation of Māori spiritual values into public life. Interactions between European colonisers and Māori have been characterised for more than 250 years by tensions between the relational thinking of Māori who see human beings as both participating in and constrained by an environment resonant with divine energies, and the quantitative, hierarchical, ‘Great Chain of Being’ model that had long been dominant among Europeans. Now, when the natural environment worldwide is under strain from population and economic pressures, it seems to some both appropriate and vital to look to epistemological and spiritual models that are intimately responsive to the specificities of location.

year: 2019