title: Synthesis and alkyne-coupling chemistry of cyclomanganated 1- and 3-acetylindoles, 3-formylindole and analogues

authors: Depree, Gary J.

subjects: cyclometallation

abstract: The syntheses are reported of new cyclomanganated indole derivatives (1-acetyl-κO-indolyl-κC2)dicarbonylbis(trimethylphosphite)manganese (2), (1-methyl-3-acetyl-κO-indolyl-κC2)tetracarbonylmanganese (4), (3-formyl-κO-indolyl-κC2)tetracarbonylmanganese (5a) and (1-methyl-3-formyl-κO-indolyl-κC2)tetracarbonylmanganese (5b). The unusually complicated crystal structure of 5b has been determined, the first for a cyclomanganated aryl aldehyde.
The preparations of a mitomycin-related pyrrolo-indole and related products by thermally promoted and oxidatively (Me3NO) initiated alkyne-coupling reactions of the previously known complex (1-acetyl-κO-indolyl-κC2)tetracarbonylmanganese (1) are reported for different alkynes and solvents. X-ray crystal structures are reported for the dimethyl acetylenedicarboxylate coupling product of 1 (dimethyl 1-methyl-l-hydroxypyrrolo[1,2a]-indole-2,3-dicarboxylate; 6a), and an unusually-cyclised triple insertion product 8 from the coupling of acetylene with 4, in which a cyclopentadiene moiety is η3-allyl-coordinated to Mn through only one double bond and an exocyclic carbon, but which rearranges on heating to an η5-cyclopentadienyl complex.

text: Synthesis and alkyne-coupling chemistry of cyclomanganated 1- and 3-acetylindoles, 3-formylindole and analogues The syntheses are reported of new cyclomanganated indole derivatives (1-acetyl-κO-indolyl-κC2)dicarbonylbis(trimethylphosphite)manganese (2), (1-methyl-3-acetyl-κO-indolyl-κC2)tetracarbonylmanganese (4), (3-formyl-κO-indolyl-κC2)tetracarbonylmanganese (5a) and (1-methyl-3-formyl-κO-indolyl-κC2)tetracarbonylmanganese (5b). The unusually complicated crystal structure of 5b has been determined, the first for a cyclomanganated aryl aldehyde.
The preparations of a mitomycin-related pyrrolo-indole and related products by thermally promoted and oxidatively (Me3NO) initiated alkyne-coupling reactions of the previously known complex (1-acetyl-κO-indolyl-κC2)tetracarbonylmanganese (1) are reported for different alkynes and solvents. X-ray crystal structures are reported for the dimethyl acetylenedicarboxylate coupling product of 1 (dimethyl 1-methyl-l-hydroxypyrrolo[1,2a]-indole-2,3-dicarboxylate; 6a), and an unusually-cyclised triple insertion product 8 from the coupling of acetylene with 4, in which a cyclopentadiene moiety is η3-allyl-coordinated to Mn through only one double bond and an exocyclic carbon, but which rearranges on heating to an η5-cyclopentadienyl complex.

year: 2006-02-01

title: Reprocessing of wood fibre reinforced polypropylene composites. Part II: Hygrothermal ageing and its effects

authors: Beg, Mohammad Dalour Hossen

subjects: A. Natural fibre composites

abstract: In this paper, hygrothermal ageing behaviour of virgin and reprocessed composites based on radiata pine (Pinus Radiata) wood fibre with a polypropylene (PP) matrix were investigated. Composites were produced with 40 wt% fibre and 4 wt% maleated polypropylene (MAPP) coupling agent using extrusion followed by injection moulding. Composites reprocessing was carried out using repeated pelletising and injection moulding for up to eight times. Hygrothermal ageing was carried out by immersing specimens in distilled water at 50 °C over a 9 month period. The diffusion coefficient of moisture absorption was obtained for composites by measuring water uptake of specimens at regular time intervals. It was found that the diffusion coefficient and the equilibrium moisture contents of composites decreased with increased number of times the materials were reprocessed. After hygrothermal ageing, tensile strength (TS), Young’s modulus (YM) and hardness of both virgin and reprocessed composites were found to decrease, but impact strength (IS) and failure strain (FS) increased. The thermal stability of both virgin and reprocessed composites was found to decrease after hygrothermal ageing.

text: Reprocessing of wood fibre reinforced polypropylene composites. Part II: Hygrothermal ageing and its effects In this paper, hygrothermal ageing behaviour of virgin and reprocessed composites based on radiata pine (Pinus Radiata) wood fibre with a polypropylene (PP) matrix were investigated. Composites were produced with 40 wt% fibre and 4 wt% maleated polypropylene (MAPP) coupling agent using extrusion followed by injection moulding. Composites reprocessing was carried out using repeated pelletising and injection moulding for up to eight times. Hygrothermal ageing was carried out by immersing specimens in distilled water at 50 °C over a 9 month period. The diffusion coefficient of moisture absorption was obtained for composites by measuring water uptake of specimens at regular time intervals. It was found that the diffusion coefficient and the equilibrium moisture contents of composites decreased with increased number of times the materials were reprocessed. After hygrothermal ageing, tensile strength (TS), Young’s modulus (YM) and hardness of both virgin and reprocessed composites were found to decrease, but impact strength (IS) and failure strain (FS) increased. The thermal stability of both virgin and reprocessed composites was found to decrease after hygrothermal ageing.

year: 2008

title: Exploring the experiences of Māori Wāhine in a STEM project-based secondary classroom: A relational and intersectional perspective

authors: Cheryl, Mitchell

abstract: Using phenomenology, an intersectional lens, and the principles of Kaupapa Māori research, this study investigates how young Māori (Indigenous) wāhine (women) ākonga (students) experience interdisciplinary project-based STEM education. Historical educational policies in Aotearoa New Zealand required Māori to assimilate into a Pākehā (European) school system, contributing to persistent academic underperformance, particularly in science. Māori have been more likely to leave school early, and those who remain often opt out of science subjects, especially Māori wāhine. International literature suggests that transdisciplinary STEM education grounded in social justice and equity can improve engagement and outcomes for underrepresented learners. The study was guided by two questions: (1) how Māori wāhine experienced the STEM programme, and (2) what their challenges were to succeed in STEM.

In 2016, while teaching at a low-decile (socioeconomic disadvantaged), urban, co-educational English-medium high school, I trialled an integrated, interdisciplinary project-based STEM class that incorporated meaningful phenomena and culturally responsive pedagogy. The class’s success led to STEM becoming a core component of a broader school initiative. In 2018, the seven Māori wāhine ākonga enrolled in the Year 11 (age 15–16) STEM class were invited to become “Story Sharers” and reflect on their experiences. As a teacher-researcher (insider), I used reflexive practices and clear role delineation to leverage contextual knowledge while minimising bias. Narrative data were collected over two years (2018–2019) through six semi-structured discussion groups and one individual interview. Quantitative data included tracking attendance records, retention, and academic achievement.

Findings indicate that the Story Sharers valued co-constructed topics and tasks, a supportive whānau (family/community) class format, and authentic project work undertaken over extended learning periods. They consistently identified strengthened relationships, particularly among peers as central to engagement, wellbeing, motivation to learn, and as the most salient indicator of success. Academic performance increased relative to prior Year-10 e-asTTle (Electronic Assessment Tool for Teaching and Learning in mathematics, reading, and writing) benchmarks, alongside improved STEM class attendance, retention in school, and intentions to continue in STEM.

Interpretive thematic analysis using an intersectional lens revealed that racism, stereotyping, and impacts on wellbeing were significant barriers to learning. These discriminatory experiences were pervasive across school, community, and online spaces and were compounded by gendered and intergenerational dynamics. The Story Sharers described complex, fluid, and intersecting identities shaped by lived experiences, including witnessing discrimination against Māori wāhine in their whānau and the legacy of colonial schooling practices such as the suppression of te reo Māori.

In this study, STEM project-based learning was shaped by two interwoven design elements: relational pedagogy and relational thinking. Relational pedagogy prioritised relationships and co-construction within a whānau-formatted classroom. Relational thinking described the interdisciplinary logic of the programme itself, connecting disciplinary knowledge to place, context, and community so that learning is organised around meaningful phenomena rather than siloed subjects. Together, these elements functioned as a counterspace that fostered inclusive engagement, affirmed identities, and supported belonging for Māori wāhine. Grounded in culturally responsive and whānau-based approaches, this model enabled learners to challenge deficit narratives and engage meaningfully in STEM. The outcomes offer assurance that integrated, project-based STEM education, underpinned by these relational frameworks, can improve outcomes for learners whose identities and experiences have been marginalised in traditional schooling. However, policymakers must remain attentive to historical policy barriers and intersectional factors that continue to perpetuate inequities within the education system.

text: Exploring the experiences of Māori Wāhine in a STEM project-based secondary classroom: A relational and intersectional perspective Using phenomenology, an intersectional lens, and the principles of Kaupapa Māori research, this study investigates how young Māori (Indigenous) wāhine (women) ākonga (students) experience interdisciplinary project-based STEM education. Historical educational policies in Aotearoa New Zealand required Māori to assimilate into a Pākehā (European) school system, contributing to persistent academic underperformance, particularly in science. Māori have been more likely to leave school early, and those who remain often opt out of science subjects, especially Māori wāhine. International literature suggests that transdisciplinary STEM education grounded in social justice and equity can improve engagement and outcomes for underrepresented learners. The study was guided by two questions: (1) how Māori wāhine experienced the STEM programme, and (2) what their challenges were to succeed in STEM.

In 2016, while teaching at a low-decile (socioeconomic disadvantaged), urban, co-educational English-medium high school, I trialled an integrated, interdisciplinary project-based STEM class that incorporated meaningful phenomena and culturally responsive pedagogy. The class’s success led to STEM becoming a core component of a broader school initiative. In 2018, the seven Māori wāhine ākonga enrolled in the Year 11 (age 15–16) STEM class were invited to become “Story Sharers” and reflect on their experiences. As a teacher-researcher (insider), I used reflexive practices and clear role delineation to leverage contextual knowledge while minimising bias. Narrative data were collected over two years (2018–2019) through six semi-structured discussion groups and one individual interview. Quantitative data included tracking attendance records, retention, and academic achievement.

Findings indicate that the Story Sharers valued co-constructed topics and tasks, a supportive whānau (family/community) class format, and authentic project work undertaken over extended learning periods. They consistently identified strengthened relationships, particularly among peers as central to engagement, wellbeing, motivation to learn, and as the most salient indicator of success. Academic performance increased relative to prior Year-10 e-asTTle (Electronic Assessment Tool for Teaching and Learning in mathematics, reading, and writing) benchmarks, alongside improved STEM class attendance, retention in school, and intentions to continue in STEM.

Interpretive thematic analysis using an intersectional lens revealed that racism, stereotyping, and impacts on wellbeing were significant barriers to learning. These discriminatory experiences were pervasive across school, community, and online spaces and were compounded by gendered and intergenerational dynamics. The Story Sharers described complex, fluid, and intersecting identities shaped by lived experiences, including witnessing discrimination against Māori wāhine in their whānau and the legacy of colonial schooling practices such as the suppression of te reo Māori.

In this study, STEM project-based learning was shaped by two interwoven design elements: relational pedagogy and relational thinking. Relational pedagogy prioritised relationships and co-construction within a whānau-formatted classroom. Relational thinking described the interdisciplinary logic of the programme itself, connecting disciplinary knowledge to place, context, and community so that learning is organised around meaningful phenomena rather than siloed subjects. Together, these elements functioned as a counterspace that fostered inclusive engagement, affirmed identities, and supported belonging for Māori wāhine. Grounded in culturally responsive and whānau-based approaches, this model enabled learners to challenge deficit narratives and engage meaningfully in STEM. The outcomes offer assurance that integrated, project-based STEM education, underpinned by these relational frameworks, can improve outcomes for learners whose identities and experiences have been marginalised in traditional schooling. However, policymakers must remain attentive to historical policy barriers and intersectional factors that continue to perpetuate inequities within the education system.

year: 2025-10-17