title: Synthesis and characterisation of ferrocenyl-phosphonic and -arsonic

authors: Alley, Steven R.

subjects: ferrocene

abstract: The ferrocene-derived acids FcCH₂CH₂E(O)(OH)₂ [4, E=P; 10, E=As; Fc=Fe(η₅-C₅H₅)(η⁵-C₅H₄)] have been synthesized by the reaction of FcCH₂CH₂Br with either P(OEt)₃ followed by hydrolysis, or with sodium arsenite followed by acidification. Reaction of FcCH₂OH with (EtO)₂P(O)Na gave FcP(O)(OEt)(OH), which was converted to FcCH₂P(O)(OH)₂ (3) by silyl ester hydrolysis using Me₃SiBr–Et₃N followed by aqueous work-up. Similarly, the known phosphonic acid FcP(O)(OH)₂and the new derivatives 1,1′-Fc′[P(O)(OH)₂]₂ [Fc′=Fe(η⁵-C₅H₄)₂] and 1,1′-Fc′[CH₂P(O)(OH)₂]₂(7) have been synthesized via their corresponding esters. X-ray crystal structure determinations have been carried out on 3 and 7, and the hydrogen-bonding networks discussed. Electrospray mass spectrometry has been employed in the characterization of the various acids. Phosphonic acids give the expected [M–H]− ions and their fragmentation at elevated cone voltages has been found to be dependent on the acid. FcP(O)(OH)₂ fragments to [C₅H₄PO₂H]−, but in contrast Fc(CH₂)nP(O)(OH)₂ (n=1, 2) give Fe{η⁵-C₅H₄(CH₂)nP(O)O₂]− ions, which are proposed to have an intramolecular interaction between the Fe atom and the phosphonate group. In contrast, arsonic acid (10), together with PhAs(O)(OH)₂for comparison, undergo facile alkylation (in methanol or ethanol solvent), and at elevated cone voltages (e.g. >60 V) undergo carbon–arsenic bond cleavage giving [CpFeAs(O)(OR)O]− (R=H, Me, Et) and ultimately [AsO₂]− ions.

text: Synthesis and characterisation of ferrocenyl-phosphonic and -arsonic The ferrocene-derived acids FcCH₂CH₂E(O)(OH)₂ [4, E=P; 10, E=As; Fc=Fe(η₅-C₅H₅)(η⁵-C₅H₄)] have been synthesized by the reaction of FcCH₂CH₂Br with either P(OEt)₃ followed by hydrolysis, or with sodium arsenite followed by acidification. Reaction of FcCH₂OH with (EtO)₂P(O)Na gave FcP(O)(OEt)(OH), which was converted to FcCH₂P(O)(OH)₂ (3) by silyl ester hydrolysis using Me₃SiBr–Et₃N followed by aqueous work-up. Similarly, the known phosphonic acid FcP(O)(OH)₂and the new derivatives 1,1′-Fc′[P(O)(OH)₂]₂ [Fc′=Fe(η⁵-C₅H₄)₂] and 1,1′-Fc′[CH₂P(O)(OH)₂]₂(7) have been synthesized via their corresponding esters. X-ray crystal structure determinations have been carried out on 3 and 7, and the hydrogen-bonding networks discussed. Electrospray mass spectrometry has been employed in the characterization of the various acids. Phosphonic acids give the expected [M–H]− ions and their fragmentation at elevated cone voltages has been found to be dependent on the acid. FcP(O)(OH)₂ fragments to [C₅H₄PO₂H]−, but in contrast Fc(CH₂)nP(O)(OH)₂ (n=1, 2) give Fe{η⁵-C₅H₄(CH₂)nP(O)O₂]− ions, which are proposed to have an intramolecular interaction between the Fe atom and the phosphonate group. In contrast, arsonic acid (10), together with PhAs(O)(OH)₂for comparison, undergo facile alkylation (in methanol or ethanol solvent), and at elevated cone voltages (e.g. >60 V) undergo carbon–arsenic bond cleavage giving [CpFeAs(O)(OR)O]− (R=H, Me, Et) and ultimately [AsO₂]− ions.

year: 2001

title: Erosional history of the Karkonosze Granite Massif – constraints from adjacent sedimentary basins and thermochronology

authors: Migoń, Piotr

subjects: Erosional history

abstract: The long-term erosional history of the Karkonosze Granite Massif is revised and reconstructed using different sources of information, including the sedimentary record of adjacent basins, previously published low-temperature thermochronological data and geomorphic features. Although the evidence is still incomplete, this work has identified a number of intervals, of unequal duration, characterized by different denudation regimes and rates. Several major phases of rapid exhumation are inferred - in the Permian and the Early Triassic as seen in the sedimentary record, and in the Late Cretaceous as shown by both the thermochronological and sedimentary records. Neotectonic uplift of the Karkonosze Mts. in the late Cenozoic is not recorded in the thermochronological record and there is no evidence of any accelerated denudation close to the massif. Apatite fission track data show that >~3.6 km of rock must have been eroded since the Turonian, while the results of zircon (U-Th)/He analysis suggest that in places erosion of >~6 km of rock must have taken place. This picture differs from previous estimates of denudation which suggested that only 2-2.5 km has been eroded from the axial part of the Karkonosze dome since the exposure of granite batholith in the Permian.

text: Erosional history of the Karkonosze Granite Massif – constraints from adjacent sedimentary basins and thermochronology The long-term erosional history of the Karkonosze Granite Massif is revised and reconstructed using different sources of information, including the sedimentary record of adjacent basins, previously published low-temperature thermochronological data and geomorphic features. Although the evidence is still incomplete, this work has identified a number of intervals, of unequal duration, characterized by different denudation regimes and rates. Several major phases of rapid exhumation are inferred - in the Permian and the Early Triassic as seen in the sedimentary record, and in the Late Cretaceous as shown by both the thermochronological and sedimentary records. Neotectonic uplift of the Karkonosze Mts. in the late Cenozoic is not recorded in the thermochronological record and there is no evidence of any accelerated denudation close to the massif. Apatite fission track data show that >~3.6 km of rock must have been eroded since the Turonian, while the results of zircon (U-Th)/He analysis suggest that in places erosion of >~6 km of rock must have taken place. This picture differs from previous estimates of denudation which suggested that only 2-2.5 km has been eroded from the axial part of the Karkonosze dome since the exposure of granite batholith in the Permian.

year: 2012

title: Waiwhakareke Restoration Plantings: Establishment of Monitoring Plots 2005-06

authors: Grove, E.

subjects: New Zealand

abstract: Waiwhakareke Natural Heritage Park is being developed to reconstruct native lowland and wetland ecosystems as were once widespread in the Waikato Region. The 60ha Natural Heritage Park is located on the north-west outskirts of Hamilton City and includes a peat lake (Horseshoe Lake) which is surrounded by introduced willow trees. There is some native marginal vegetation around the lake, including rushes and sedges, and an extensive area of gently sloping pasture completes the catchment. The restoration and recreation of the native plant and animal communities is being lead by the Hamilton City Council in partnership with The University of Waikato, Wintec, Nga Mana Toopu o Kirikiriroa Limited Resource Management and Cultural Consultants and Tui 2000 (McQueen 2005; McQueen & Clarkson 2003).

text: Waiwhakareke Restoration Plantings: Establishment of Monitoring Plots 2005-06 Waiwhakareke Natural Heritage Park is being developed to reconstruct native lowland and wetland ecosystems as were once widespread in the Waikato Region. The 60ha Natural Heritage Park is located on the north-west outskirts of Hamilton City and includes a peat lake (Horseshoe Lake) which is surrounded by introduced willow trees. There is some native marginal vegetation around the lake, including rushes and sedges, and an extensive area of gently sloping pasture completes the catchment. The restoration and recreation of the native plant and animal communities is being lead by the Hamilton City Council in partnership with The University of Waikato, Wintec, Nga Mana Toopu o Kirikiriroa Limited Resource Management and Cultural Consultants and Tui 2000 (McQueen 2005; McQueen & Clarkson 2003).

year: 2006