title: Using ESI-MS to investigate the organometallic compound Cp₂Ti(SC₆H₄CO₂) and closely related compounds

authors: Song, Kai

subjects: ESI-MS

abstract: This thesis reports investigations on the electrospray ionisation mass spectrometric (ESI-MS) behaviour of some metallocene complexes of titanium and molybdenum. The ESI-MS behaviour of titanocene dichloride (Cp₂TiCl₂) compound, which is has shown of interest as an anticancer agent was investigated. Cp₂TiCl₂ was dissolved in various solvents and spectra were recorded at various capillary exit voltages from 60 V to 250 V. Bis(ethylcyclopentadienyl) dichloridotitanium(IV) was also studied via ESI-MS. Results indicated clearly some main species like [Cp₂TiH]⁺, [Cp₂Ti(OCH₃)]⁺ and [Cp₂Ti(OCH₃)₂+H]⁺ were observed. When the capillary exit voltage was greater than 150 V species containing two Ti centres like [Cp₄Ti₂(OCH₃)₂Cl]⁺, [Cp₄Ti₂(OCH₃)₃Cl+H]⁺ and [(Cp₂Ti(OCH₃)₂+H⁺)₂+Cl]⁻ disappeared and titanocene(III) species [Cp₂Ti(CH₃OH)]⁺ was observed which indicated reduction of titanium(IV) during ESI-MS analysis. Larger ions which contain three or more Ti centres were not observed. 

The main focus of this thesis was to investigate the chemistry and characterisation of the organometallic compound bis(cyclopentadienyl) thiosalicylatotitanium(IV) (Cp₂Ti(tsal) tsal = SC₆H₄CO₂). A further experiment was done to run the spectrum of a mixed solution of Cp₂TiCl₂ and Cp₂Ti(tsal) in CH₃OH to investigate the possibility of the tsal ligand bridging two Cp₂Ti centres. Characterisation of Cp₂Ti(tsal) using ESI mass spectrometry in the presence of added alkali metal salts and the reactivity of Cp₂Ti(tsal) towards soft electrophile was also studied.

At the same time, a new complex bis(ethylcyclopentadienyl) thiosalicylatotitanium(IV) ((EtCp)₂Ti(tsal)) was synthesised and studied by ESI-MS. Comparison of the ESI-MS spectra of Cp₂Ti(tsal) with those of (EtCp)₂Ti(tsal) was used to confirm the identity of some unknown species. This new complex was characterised by elemental analysis, melting point, nuclear magnetic resonance (NMR) and infra-red (IR) spectroscopy.

Finally the molybdocene dichloride (Cp₂MoCl₂) compound was studied by ESI-MS. The closely related compound bis(cyclopentadienyl) thiosalicylatomolybdenum(IV)  (Cp₂Mo(tsal)) was synthesised and characterised by ESI-MS, melting point, NMR and IR spectroscopy. Less species can be observed in the Mo system than in the Ti system. Most species in the Mo system contained a Cl ligand.

text: Using ESI-MS to investigate the organometallic compound Cp₂Ti(SC₆H₄CO₂) and closely related compounds This thesis reports investigations on the electrospray ionisation mass spectrometric (ESI-MS) behaviour of some metallocene complexes of titanium and molybdenum. The ESI-MS behaviour of titanocene dichloride (Cp₂TiCl₂) compound, which is has shown of interest as an anticancer agent was investigated. Cp₂TiCl₂ was dissolved in various solvents and spectra were recorded at various capillary exit voltages from 60 V to 250 V. Bis(ethylcyclopentadienyl) dichloridotitanium(IV) was also studied via ESI-MS. Results indicated clearly some main species like [Cp₂TiH]⁺, [Cp₂Ti(OCH₃)]⁺ and [Cp₂Ti(OCH₃)₂+H]⁺ were observed. When the capillary exit voltage was greater than 150 V species containing two Ti centres like [Cp₄Ti₂(OCH₃)₂Cl]⁺, [Cp₄Ti₂(OCH₃)₃Cl+H]⁺ and [(Cp₂Ti(OCH₃)₂+H⁺)₂+Cl]⁻ disappeared and titanocene(III) species [Cp₂Ti(CH₃OH)]⁺ was observed which indicated reduction of titanium(IV) during ESI-MS analysis. Larger ions which contain three or more Ti centres were not observed. 

The main focus of this thesis was to investigate the chemistry and characterisation of the organometallic compound bis(cyclopentadienyl) thiosalicylatotitanium(IV) (Cp₂Ti(tsal) tsal = SC₆H₄CO₂). A further experiment was done to run the spectrum of a mixed solution of Cp₂TiCl₂ and Cp₂Ti(tsal) in CH₃OH to investigate the possibility of the tsal ligand bridging two Cp₂Ti centres. Characterisation of Cp₂Ti(tsal) using ESI mass spectrometry in the presence of added alkali metal salts and the reactivity of Cp₂Ti(tsal) towards soft electrophile was also studied.

At the same time, a new complex bis(ethylcyclopentadienyl) thiosalicylatotitanium(IV) ((EtCp)₂Ti(tsal)) was synthesised and studied by ESI-MS. Comparison of the ESI-MS spectra of Cp₂Ti(tsal) with those of (EtCp)₂Ti(tsal) was used to confirm the identity of some unknown species. This new complex was characterised by elemental analysis, melting point, nuclear magnetic resonance (NMR) and infra-red (IR) spectroscopy.

Finally the molybdocene dichloride (Cp₂MoCl₂) compound was studied by ESI-MS. The closely related compound bis(cyclopentadienyl) thiosalicylatomolybdenum(IV)  (Cp₂Mo(tsal)) was synthesised and characterised by ESI-MS, melting point, NMR and IR spectroscopy. Less species can be observed in the Mo system than in the Ti system. Most species in the Mo system contained a Cl ligand.

year: 2019

title: Teacher education for an uncertain future: Implications of PISA’s global competence

authors: Cobb, Donella J.

abstract: In 2018, the Organisation for Economic Cooperation and Development’s (OECD) is set to introduce an assessment of Global Competence in its Programme for International Student Achievement (PISA). This assessment lays the foundation for a set of knowledge, skills, values and beliefs that the OECD considers necessary to become a globally competent citizen. Throughout this chapter, we identify and critique the intended socialising function of PISA’s Global Competence and consider its implications for Initial Teacher Education (ITE). We do this by drawing on Bernstein’s theoretical tools to engage in a critical analysis of PISA’s Global Competence framework. Our analysis reveals three key findings: (1) PISA’s Global Competence acts as a symbolic regulator of consciousness, (2) PISA’s Global Competence facilitates a new form of global pedagogic governance and (3) ITE can play an important role in either reproducing, disrupting or transforming the socialising function of PISA’s Global Competence. In conclusion, we argue that engaging with Comparative and International Education scholarship will prepare pre-service teachers to respond to the complexities and demands of an uncertain educational future within an increasingly globalised educational landscape.

text: Teacher education for an uncertain future: Implications of PISA’s global competence In 2018, the Organisation for Economic Cooperation and Development’s (OECD) is set to introduce an assessment of Global Competence in its Programme for International Student Achievement (PISA). This assessment lays the foundation for a set of knowledge, skills, values and beliefs that the OECD considers necessary to become a globally competent citizen. Throughout this chapter, we identify and critique the intended socialising function of PISA’s Global Competence and consider its implications for Initial Teacher Education (ITE). We do this by drawing on Bernstein’s theoretical tools to engage in a critical analysis of PISA’s Global Competence framework. Our analysis reveals three key findings: (1) PISA’s Global Competence acts as a symbolic regulator of consciousness, (2) PISA’s Global Competence facilitates a new form of global pedagogic governance and (3) ITE can play an important role in either reproducing, disrupting or transforming the socialising function of PISA’s Global Competence. In conclusion, we argue that engaging with Comparative and International Education scholarship will prepare pre-service teachers to respond to the complexities and demands of an uncertain educational future within an increasingly globalised educational landscape.

year: 2018

title: Māori Waiata: Discourse structuring, sub-genres and aesthetics

authors: Roa, Raukura

subjects: Te reo Māori

abstract: With particular reference to a discourse-based analysis of five waiata tangi from Ngāti Hauā, it is argued here that different types of Māori waiata (songs and chants) may be characterised by different types of overall discourse structuring. It is also suggested that discourse structuring may be a significant aspect of the aesthetics of Māori waiata.

text: Māori Waiata: Discourse structuring, sub-genres and aesthetics With particular reference to a discourse-based analysis of five waiata tangi from Ngāti Hauā, it is argued here that different types of Māori waiata (songs and chants) may be characterised by different types of overall discourse structuring. It is also suggested that discourse structuring may be a significant aspect of the aesthetics of Māori waiata.

year: 2004-02