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: Dating painted Panel E1 at Nawarla Gabarnmang, central-western Arnhem Land plateau

authors: David, Bruno O.

abstract: Western Arnhem Land, in the Top End of Australia’s Northern Territory, has a rich archaeological landscape, ethnographic record and body of rock art that displays an astonishing array of imagery on shelter walls and ceilings. While the archaeology goes back to the earliest period of Aboriginal occupation of the continent, the rock art represents some of the richest, most diverse and visually most impressive regional assemblages anywhere in the world. To better understand this multi-dimensional cultural record, The Archaeology of Rock Art in Western Arnhem Land, Australia focuses on the nature and antiquity of the region’s rock art as revealed by archaeological surveys and excavations, and the application of novel analytical methods. This volume also presents new findings by which to rethink how Aboriginal peoples have socially engaged in and with places across western Arnhem Land, from the north to the south, from the plains to the spectacular rocky landscapes of the plateau. The dynamic nature of Arnhem Land rock art is explored and articulated in innovative ways that shed new light on the region’s deep time Aboriginal history.

text: Dating painted Panel E1 at Nawarla Gabarnmang, central-western Arnhem Land plateau Western Arnhem Land, in the Top End of Australia’s Northern Territory, has a rich archaeological landscape, ethnographic record and body of rock art that displays an astonishing array of imagery on shelter walls and ceilings. While the archaeology goes back to the earliest period of Aboriginal occupation of the continent, the rock art represents some of the richest, most diverse and visually most impressive regional assemblages anywhere in the world. To better understand this multi-dimensional cultural record, The Archaeology of Rock Art in Western Arnhem Land, Australia focuses on the nature and antiquity of the region’s rock art as revealed by archaeological surveys and excavations, and the application of novel analytical methods. This volume also presents new findings by which to rethink how Aboriginal peoples have socially engaged in and with places across western Arnhem Land, from the north to the south, from the plains to the spectacular rocky landscapes of the plateau. The dynamic nature of Arnhem Land rock art is explored and articulated in innovative ways that shed new light on the region’s deep time Aboriginal history.

year: 2017

title: Te Hokinga ki te Pā Harakeke

authors: Hohepa, Margie Kahukura

abstract: 'Tiakina Te Pā Harakeke' investigates the collective values that nourish and enhances the well-being of tamariki Māori as taonga within our whānau, hapū and iwi. lt explores ways in which Māori values and tikanga are harnessed in contemporary whānau contexts to provide safe, vibrant and enriched childrearing. parenting and child-focussed strategies.

text: Te Hokinga ki te Pā Harakeke 'Tiakina Te Pā Harakeke' investigates the collective values that nourish and enhances the well-being of tamariki Māori as taonga within our whānau, hapū and iwi. lt explores ways in which Māori values and tikanga are harnessed in contemporary whānau contexts to provide safe, vibrant and enriched childrearing. parenting and child-focussed strategies.

year: 2014