title: Dimeric rhodium(III), iridium(III) and ruthenium(II) thiosalicylate complexes

authors: Henderson, William

subjects: Rhodium

abstract: Reactions of the chloride-bridged dimers [LMCl(μ-Cl)]₂ (M=Rh, Ir; L=Cp*=η⁵-C₅Me₅; M=Ru, L=η⁶-p-cymene) with two mole equivalents of thiosalicylic acid (HSC₆H₄CO₂H, H₂tsal) and excess base gives the dimeric rhodium(III), iridium(III) and ruthenium(II) thiosalicylate complexes [LM(tsal)]₂. Reaction of the complex [Cp*RhCl₂(PPh₂)] with one equivalent of H₂tsal and triethylamine in dichloromethane gives a mixture of the dimer [Cp*Rh(tsal)]₂ and the phosphine complex [Cp*Rh(tsal)(PPh₃)]; upon recrystallisation, pure dimer is obtained. A single-crystal X-ray diffraction study on the rhodium and ruthenium dimers reveals the expected thiolate-bridged M₂(μ-S)₂ unit. Electrospray mass spectrometry (ESMS) is a useful technique in studying the chemistry of the thiosalicylate complexes, all complexes giving strong [M+H]⁺ ions. With added thiosalicylic acid, cations of the type [(LM)₂(Htsal)₃]⁺ were detected in the mass spectra.

text: Dimeric rhodium(III), iridium(III) and ruthenium(II) thiosalicylate complexes Reactions of the chloride-bridged dimers [LMCl(μ-Cl)]₂ (M=Rh, Ir; L=Cp*=η⁵-C₅Me₅; M=Ru, L=η⁶-p-cymene) with two mole equivalents of thiosalicylic acid (HSC₆H₄CO₂H, H₂tsal) and excess base gives the dimeric rhodium(III), iridium(III) and ruthenium(II) thiosalicylate complexes [LM(tsal)]₂. Reaction of the complex [Cp*RhCl₂(PPh₂)] with one equivalent of H₂tsal and triethylamine in dichloromethane gives a mixture of the dimer [Cp*Rh(tsal)]₂ and the phosphine complex [Cp*Rh(tsal)(PPh₃)]; upon recrystallisation, pure dimer is obtained. A single-crystal X-ray diffraction study on the rhodium and ruthenium dimers reveals the expected thiolate-bridged M₂(μ-S)₂ unit. Electrospray mass spectrometry (ESMS) is a useful technique in studying the chemistry of the thiosalicylate complexes, all complexes giving strong [M+H]⁺ ions. With added thiosalicylic acid, cations of the type [(LM)₂(Htsal)₃]⁺ were detected in the mass spectra.

year: 2001-04-01

title: Sedimentology and tephrochronology of last-glacial and holocene lake sediments and peat from south Westland, New Zealand

authors: Cole-Baker, Jeremy R.

subjects: geology

abstract: A high resolution study of lake sediments and peat from three ice marginal sites in South Westland was carried out with the aim of determining the nature and timing of abrupt climate change during the last glaciation and the glacial-interglacial transition. The flux and composition of aeolian dust were used as proxies for the extent of exposed outwash surfaces and hence the extent of ice advance in the vicinity of the core sites. Cores were collected from Skiffington Swamp, Galway Tarn, and Okarito Pakihi in South Westland and the sediments characterised by measuring magnetic susceptibility (MS), combustible organic carbon (COC), grain size and mineralogy. Previously analysed pollen assemblages (Vandergoes, 2000; Vandergoes and Fitzsimons, 2003; Vandergoes et al., 2005; M. J. Vandergoes, unpublished data) were correlated with the data from this study to interpret the relationship between climate and glacial extent. Cores from Skiffington Swamp and Galway Tarn contained a visible tephra layer identified as the Kawakawa Tephra (c. 26,500 cal. years B.P.) based on stratigraphic position and glass shard composition. This layer provided an excellent chronostratigraphic reference point. 
The results from this study show that between 58,000 and 38,000 cal. years B.P., the climate was cool and variable in South Westland. Minor glacier advances occurred within a few kilometres of the Southern Alps. More significant glacier advance was recorded by MS and COC data at Skiffington Swamp after 38,000 cal. years B.P., which implies that glacial advance occurred earlier than the climate cooling recorded by pollen studies. Data from the most distal site (Galway Tarn, located approximately 10 km to the west of Skiffington Swamp) show that ice advanced near to that site at 32,000 cal. years B.P. This marks the start of maximum post-MIS 4 glacier extent. MS values were lowered at Skiffington Swamp during the interval from 30,000 to 22,000 cal. years B.P., indicating that the glacier margins and outwash plains were located well to the west. A decline in MS values at Galway Tarn and a peak in MS values at Skiffington Swamp occurred at 20,000 cal. years B.P., as glaciers retreated and outwash areas moved closer to the Southern Alps. There is no clear evidence at these three sites for a late glacial ice advance. Any such advance had limited impact 10-20 km from the present ice position.

text: Sedimentology and tephrochronology of last-glacial and holocene lake sediments and peat from south Westland, New Zealand A high resolution study of lake sediments and peat from three ice marginal sites in South Westland was carried out with the aim of determining the nature and timing of abrupt climate change during the last glaciation and the glacial-interglacial transition. The flux and composition of aeolian dust were used as proxies for the extent of exposed outwash surfaces and hence the extent of ice advance in the vicinity of the core sites. Cores were collected from Skiffington Swamp, Galway Tarn, and Okarito Pakihi in South Westland and the sediments characterised by measuring magnetic susceptibility (MS), combustible organic carbon (COC), grain size and mineralogy. Previously analysed pollen assemblages (Vandergoes, 2000; Vandergoes and Fitzsimons, 2003; Vandergoes et al., 2005; M. J. Vandergoes, unpublished data) were correlated with the data from this study to interpret the relationship between climate and glacial extent. Cores from Skiffington Swamp and Galway Tarn contained a visible tephra layer identified as the Kawakawa Tephra (c. 26,500 cal. years B.P.) based on stratigraphic position and glass shard composition. This layer provided an excellent chronostratigraphic reference point. 
The results from this study show that between 58,000 and 38,000 cal. years B.P., the climate was cool and variable in South Westland. Minor glacier advances occurred within a few kilometres of the Southern Alps. More significant glacier advance was recorded by MS and COC data at Skiffington Swamp after 38,000 cal. years B.P., which implies that glacial advance occurred earlier than the climate cooling recorded by pollen studies. Data from the most distal site (Galway Tarn, located approximately 10 km to the west of Skiffington Swamp) show that ice advanced near to that site at 32,000 cal. years B.P. This marks the start of maximum post-MIS 4 glacier extent. MS values were lowered at Skiffington Swamp during the interval from 30,000 to 22,000 cal. years B.P., indicating that the glacier margins and outwash plains were located well to the west. A decline in MS values at Galway Tarn and a peak in MS values at Skiffington Swamp occurred at 20,000 cal. years B.P., as glaciers retreated and outwash areas moved closer to the Southern Alps. There is no clear evidence at these three sites for a late glacial ice advance. Any such advance had limited impact 10-20 km from the present ice position.

year: 2006

title: Racism and Employment: A Narrative Review of Aotearoa New Zealand and International Qualitative Studies

authors: Tan, Kyle K. H.

abstract: In Aotearoa New Zealand, employment inequities exist for minoritised ethnic groups (Māori, Pasifika, Asian, racialised migrants and refugees) in the forms of barriers to employment, occupation inequities, differences in promotion to leadership roles, ethnic pay gaps and discriminatory experiences at workplaces. In this review, we compiled Aotearoa qualitative studies to depict the dynamics of racism alongside other intersectional forms of prejudices that disadvantage the employment processes and career progression of minoritised ethnicities. Literature gaps in Aotearoa research were identified through reviewing international literature published between 2016 and 2021. Reviewed Aotearoa studies were categorised into three themes: unemployment and underemployment, workplace discrimination, and strategies for navigating racism. Drawing upon a framework that recognises racialised processes as spanning across micro- (individual), meso- (organisational) and macro- (institutional) levels, we found most Aotearoa studies analysing racism in the workplace focus on micro-level experiences. Compared with international literature, research in Aotearoa has yet to consider the roles of organisations and technologies as racialised structures that engender employment inequities, and the interaction of individuals in response to meso- and macro-structures that build on settler colonialism and racism. Our review echoes the call of Aotearoa scholars to name racism as the overarching oppressive mechanism embedded within organisations and to use anti-racism praxes such as te Tiriti o Waitangi as a way forward to promote employment equity.

text: Racism and Employment: A Narrative Review of Aotearoa New Zealand and International Qualitative Studies In Aotearoa New Zealand, employment inequities exist for minoritised ethnic groups (Māori, Pasifika, Asian, racialised migrants and refugees) in the forms of barriers to employment, occupation inequities, differences in promotion to leadership roles, ethnic pay gaps and discriminatory experiences at workplaces. In this review, we compiled Aotearoa qualitative studies to depict the dynamics of racism alongside other intersectional forms of prejudices that disadvantage the employment processes and career progression of minoritised ethnicities. Literature gaps in Aotearoa research were identified through reviewing international literature published between 2016 and 2021. Reviewed Aotearoa studies were categorised into three themes: unemployment and underemployment, workplace discrimination, and strategies for navigating racism. Drawing upon a framework that recognises racialised processes as spanning across micro- (individual), meso- (organisational) and macro- (institutional) levels, we found most Aotearoa studies analysing racism in the workplace focus on micro-level experiences. Compared with international literature, research in Aotearoa has yet to consider the roles of organisations and technologies as racialised structures that engender employment inequities, and the interaction of individuals in response to meso- and macro-structures that build on settler colonialism and racism. Our review echoes the call of Aotearoa scholars to name racism as the overarching oppressive mechanism embedded within organisations and to use anti-racism praxes such as te Tiriti o Waitangi as a way forward to promote employment equity.

year: 2024-01-01