title: The reactions of group IVB hydrides with carbonyl complexes of cobalt and manganese

authors: Foster, Stephen Paul

abstract: The use of the hydrides as reagents for building group IVB - transition metal complexes has been investigated.

The reactions of the simple hydrides; Me₃GeH, Me₂GeH₂, MeGeH₃, GeH₄, Me₂SiH₂, Me₂SnH₂, MeSnH₃, and SnH₄, with Co₂(CO)₈ have been examined, and the effect determined of, reactant ratios and amount of CO present, on the products obtained. Limited evidence was obtained for the synthesis of the new compounds; MeGe[Co(CO)₄]₃, HGe[Co(CO)₄]₃, Me₂SiHCo(CO)₄ and (OC)₄CoMe₂SiOCCo₃(CO)₉. Me₂GeH₂ replaces a bridging CO group:

Me₂GeH₂ + Co₂(CO)₈ → Me₂GeCo₂(CO)₇ + H₂ + CO
Me₂GeH₂ + Me₂GeCo₂(CO) ₇ → (Me₂Ge)₂Co₂(CO)₆ + H₂ + CO

In the reactions of the polygermanes; Me₃GeGeH₃, Me₃SiGeH₃, Ge₂H₆, Ge₃H₈ and (GeH₃)₂SiMe₂ with Co₂(CO)₈, the M'-Ge, (M' = Si or Ge) bonds were quantitatively cleaved, and the new compound Ge₂Co₆(CO)₂₀, was isolated. This compound is assigned the structure:

on spectroscopic evidence.

Me₂GeH₂ also replaces a bridging CO group in the germanium - cobalt carbonyl species, to produce the new compounds; Me₂Ge₂Co₄(CO)₁₃ and (Me₂Ge)₂Ge₂Co₆(CO)₁₈. An X-ray crystallographic study on Me₂Ge₂Co₄(CO)₁₃ although showing the: 

skeleton, failed to refine properly. The reactions of Me₂SiH₂ and Me₂SnH₂ with germanium - cobalt carbonyl species failed to give a similar result.

MeGeH₃ and GeCo₄(Co)₁₄ produced initially the analogous Me(H)Ge₂Co₄(CO)₁₃. However when left for 6 months, an unexpected rearrangement yielded (MeGe)₂Co₄(CO)₁₁. X-ray crystallography showed an irregular square bipyramidal structure, containing 5-coordinated square pyramidal germanium. This is this first example of such a group IVB - transition metal cluster.

The decarbonylation of Ge₂Co₆(CO)₂₀ yielded the new compound [(OC)₄CoGe]₂Co₄(CO)₁₁ :


which was found by X-ray crystallography to have a similar square bipyramidal structure.
The new tin hydrides; MeSnH₂Mn(CO)₅ and Me₂SnHMn(CO)₅, have been prepared by the established route :
Me₍₃₋ₓ₎SnHₓCl + NaMn(CO)₅ → Me₍₃₋ₓ₎SnHₓMn(CO)₅ + NaCl
(x = 1,2) and characterised spectroscopically.

text: The reactions of group IVB hydrides with carbonyl complexes of cobalt and manganese The use of the hydrides as reagents for building group IVB - transition metal complexes has been investigated.

The reactions of the simple hydrides; Me₃GeH, Me₂GeH₂, MeGeH₃, GeH₄, Me₂SiH₂, Me₂SnH₂, MeSnH₃, and SnH₄, with Co₂(CO)₈ have been examined, and the effect determined of, reactant ratios and amount of CO present, on the products obtained. Limited evidence was obtained for the synthesis of the new compounds; MeGe[Co(CO)₄]₃, HGe[Co(CO)₄]₃, Me₂SiHCo(CO)₄ and (OC)₄CoMe₂SiOCCo₃(CO)₉. Me₂GeH₂ replaces a bridging CO group:

Me₂GeH₂ + Co₂(CO)₈ → Me₂GeCo₂(CO)₇ + H₂ + CO
Me₂GeH₂ + Me₂GeCo₂(CO) ₇ → (Me₂Ge)₂Co₂(CO)₆ + H₂ + CO

In the reactions of the polygermanes; Me₃GeGeH₃, Me₃SiGeH₃, Ge₂H₆, Ge₃H₈ and (GeH₃)₂SiMe₂ with Co₂(CO)₈, the M'-Ge, (M' = Si or Ge) bonds were quantitatively cleaved, and the new compound Ge₂Co₆(CO)₂₀, was isolated. This compound is assigned the structure:

on spectroscopic evidence.

Me₂GeH₂ also replaces a bridging CO group in the germanium - cobalt carbonyl species, to produce the new compounds; Me₂Ge₂Co₄(CO)₁₃ and (Me₂Ge)₂Ge₂Co₆(CO)₁₈. An X-ray crystallographic study on Me₂Ge₂Co₄(CO)₁₃ although showing the: 

skeleton, failed to refine properly. The reactions of Me₂SiH₂ and Me₂SnH₂ with germanium - cobalt carbonyl species failed to give a similar result.

MeGeH₃ and GeCo₄(Co)₁₄ produced initially the analogous Me(H)Ge₂Co₄(CO)₁₃. However when left for 6 months, an unexpected rearrangement yielded (MeGe)₂Co₄(CO)₁₁. X-ray crystallography showed an irregular square bipyramidal structure, containing 5-coordinated square pyramidal germanium. This is this first example of such a group IVB - transition metal cluster.

The decarbonylation of Ge₂Co₆(CO)₂₀ yielded the new compound [(OC)₄CoGe]₂Co₄(CO)₁₁ :


which was found by X-ray crystallography to have a similar square bipyramidal structure.
The new tin hydrides; MeSnH₂Mn(CO)₅ and Me₂SnHMn(CO)₅, have been prepared by the established route :
Me₍₃₋ₓ₎SnHₓCl + NaMn(CO)₅ → Me₍₃₋ₓ₎SnHₓMn(CO)₅ + NaCl
(x = 1,2) and characterised spectroscopically.

year: 1982

title: Leaching and uptake of nitrogen, and pasture production, associated with irrigation of treated wastewater, Taupō, New Zealand

authors: Telfer, Erin Isobel Charlotte

subjects: Wastewater

abstract: Secondary-treated wastewater from Taupō Township is irrigated onto perennial ryegrass (Lolium perenne) which is harvested and removed from the View Road wastewater treatment site. To determine the fate of the applied wastewater nitrogen, 48 undisturbed barrel lysimeters (30 cm diameter x 43 cm depth) were installed throughout 29 hectares. Centre pivot travelling irrigators were programmed to vary in speed to provide target wastewater application rates of about 0, 450, 550 and 650 kg N ha⁻¹yr⁻¹.
The targeted application treatments were not achieved, with the achieved nitrogen loading rates grouped into a low treatment (286 - 380 kg N ha⁻¹yr⁻¹), a medium treatment (380 - 445 kg N ha⁻¹yr⁻¹), and a high treatment (445 - 567 kg N ha⁻¹yr⁻¹). Nitrogen input in control sectors was assumed to be 5 kg N/ha/yr from atmospheric nitrogen deposition.
A mean of 4 to 6% of the applied nitrogen was leached. The mean amount of nitrogen leached from the high treatment (28.6 ± 10.1 kg N ha⁻¹yr⁻¹) was higher (P < 0.05) than from the low treatment (12.7 ± 4.2 kg N ha⁻¹yr⁻¹). The medium treatment (16.0 ± 7.2 kg N ha⁻¹yr⁻¹) was not significantly different than the low treatment or the high treatment. The mean amount of nitrogen leached from the control treatment was 2.8 ± 0.6 kg N ha⁻¹yr⁻¹. Nitrogen leaching that occurred in the high application treatment was below the consented limit of 30 kg N ha⁻¹yr⁻¹.
A mean of 79 to 100% of the applied nitrogen was removed by pasture. There were no significant differences in pasture dry matter production, or nitrogen removal, between the low treatment (13 922 ± 1196 kg DM ha⁻¹yr⁻¹and 341 ± 25 kg N ha⁻¹yr⁻¹), the medium treatment (13 543 ± 1475 kg DM ha⁻¹yr⁻¹ and 360 ± 51 kg N ha⁻¹yr⁻¹), and the high treatment (15 285 ± 1919 kg DM ha⁻¹yr⁻¹ and 385 ± 43 kg N ha⁻¹yr⁻¹). Pasture production was higher (P < 0.001) in irrigated pastures (mean of all irrigated treatments, 14 250 ± 349 kg DM ha⁻¹yr⁻¹) than unirrigated controls (5300 ± 839 kg DM ha⁻¹yr⁻¹).
A mean of -4 to 16% of the applied wastewater nitrogen was unaccounted for. The majority of unrecovered nitrogen was presumed to be volatilised with lower potential for denitrification and soil storage.
A second experiment was undertaken to determine whether a five week or a ten week harvesting frequency would result in greater pasture production and nitrogen removal. During the ten month trial, 265 kg N ha⁻¹ of wastewater nitrogen was irrigated and pasture plots (1 m x 1 m) were cut with a mower. Nitrogen removal and pasture production were higher (P < 0.05) with a five week harvesting interval (8231 ± 186 kg DM ha⁻¹ and 250 ± 5 kg N ha⁻¹) than a ten week harvesting interval (7354 ± 67 kg DM ha⁻¹ and 191 ± 3 kg N ha⁻¹). Harvesting at five week intervals during late-November to May (late-spring to late-autumn) and ten week intervals from May until early-November (late-autumn to mid-spring) is recommended to maximise both pasture production and nitrogen removal, while minimising harvesting costs.

text: Leaching and uptake of nitrogen, and pasture production, associated with irrigation of treated wastewater, Taupō, New Zealand Secondary-treated wastewater from Taupō Township is irrigated onto perennial ryegrass (Lolium perenne) which is harvested and removed from the View Road wastewater treatment site. To determine the fate of the applied wastewater nitrogen, 48 undisturbed barrel lysimeters (30 cm diameter x 43 cm depth) were installed throughout 29 hectares. Centre pivot travelling irrigators were programmed to vary in speed to provide target wastewater application rates of about 0, 450, 550 and 650 kg N ha⁻¹yr⁻¹.
The targeted application treatments were not achieved, with the achieved nitrogen loading rates grouped into a low treatment (286 - 380 kg N ha⁻¹yr⁻¹), a medium treatment (380 - 445 kg N ha⁻¹yr⁻¹), and a high treatment (445 - 567 kg N ha⁻¹yr⁻¹). Nitrogen input in control sectors was assumed to be 5 kg N/ha/yr from atmospheric nitrogen deposition.
A mean of 4 to 6% of the applied nitrogen was leached. The mean amount of nitrogen leached from the high treatment (28.6 ± 10.1 kg N ha⁻¹yr⁻¹) was higher (P < 0.05) than from the low treatment (12.7 ± 4.2 kg N ha⁻¹yr⁻¹). The medium treatment (16.0 ± 7.2 kg N ha⁻¹yr⁻¹) was not significantly different than the low treatment or the high treatment. The mean amount of nitrogen leached from the control treatment was 2.8 ± 0.6 kg N ha⁻¹yr⁻¹. Nitrogen leaching that occurred in the high application treatment was below the consented limit of 30 kg N ha⁻¹yr⁻¹.
A mean of 79 to 100% of the applied nitrogen was removed by pasture. There were no significant differences in pasture dry matter production, or nitrogen removal, between the low treatment (13 922 ± 1196 kg DM ha⁻¹yr⁻¹and 341 ± 25 kg N ha⁻¹yr⁻¹), the medium treatment (13 543 ± 1475 kg DM ha⁻¹yr⁻¹ and 360 ± 51 kg N ha⁻¹yr⁻¹), and the high treatment (15 285 ± 1919 kg DM ha⁻¹yr⁻¹ and 385 ± 43 kg N ha⁻¹yr⁻¹). Pasture production was higher (P < 0.001) in irrigated pastures (mean of all irrigated treatments, 14 250 ± 349 kg DM ha⁻¹yr⁻¹) than unirrigated controls (5300 ± 839 kg DM ha⁻¹yr⁻¹).
A mean of -4 to 16% of the applied wastewater nitrogen was unaccounted for. The majority of unrecovered nitrogen was presumed to be volatilised with lower potential for denitrification and soil storage.
A second experiment was undertaken to determine whether a five week or a ten week harvesting frequency would result in greater pasture production and nitrogen removal. During the ten month trial, 265 kg N ha⁻¹ of wastewater nitrogen was irrigated and pasture plots (1 m x 1 m) were cut with a mower. Nitrogen removal and pasture production were higher (P < 0.05) with a five week harvesting interval (8231 ± 186 kg DM ha⁻¹ and 250 ± 5 kg N ha⁻¹) than a ten week harvesting interval (7354 ± 67 kg DM ha⁻¹ and 191 ± 3 kg N ha⁻¹). Harvesting at five week intervals during late-November to May (late-spring to late-autumn) and ten week intervals from May until early-November (late-autumn to mid-spring) is recommended to maximise both pasture production and nitrogen removal, while minimising harvesting costs.

year: 2013

title: Re-designing the national imaginary: The development of Matariki as a contemporary festival

authors: Hardy, Ann

subjects: Aotearoa/New Zealand

abstract: This article considers the factors shaping the contemporary redevelopment in Aotearoa/ New Zealand of the indigenous commemoration of the rising of the constellation Matariki as a marker of seasonal change.  Through interviews with producers of media materials celebrating Matariki, it examines the ideological, cultural, and economic factors determining the encoding of the materials, investigating in particular the ways in which Matariki can resource a marketplace for spiritual commodities.

text: Re-designing the national imaginary: The development of Matariki as a contemporary festival This article considers the factors shaping the contemporary redevelopment in Aotearoa/ New Zealand of the indigenous commemoration of the rising of the constellation Matariki as a marker of seasonal change.  Through interviews with producers of media materials celebrating Matariki, it examines the ideological, cultural, and economic factors determining the encoding of the materials, investigating in particular the ways in which Matariki can resource a marketplace for spiritual commodities.

year: 2012