title: Organomanganese compounds in organic synthesis

authors: Prasad, Narendra Jai

subjects: cyclomanganated chalcones

abstract: This thesis describes the preparation and reactions of some cyclomanganated chalcones, dienones and aryl ketones. Investigation has previously been undertaken into the reaction of cyclomanganated chalcones and dienones with alkynes to give both pyranyl and cycloheptadienyl Mn(CO)₃ complexes. In the current study, the reaction was further investigated with a cyclomanganated dienone derived from a cyclic ketone which gave only the (pyranyl)Mn(CO)₃ complex (2-6) and not the cycloheptadienyl product as consistent with a mechanism previously proposed. Also extended in the current study was previous work involving the methylmanganese pentacarbonyl-mediated transformation of enynes to cyclopropanated bicyclic compounds and cyclopentanes bearing an exocyclic double bond. In the current study, benzylmanganese pentacarbonyl was used instead of methylmanganese pentacarbonyl under similar conditions. In the current study however, the type of product that formed in diethyl ether (3-4) was the one dominant in acetonitrile in the MeMn(CO)₅ study, and that formed in acetonitrile (3-5) was the dominant product type in diethyl ether (3-4). There was no apparent explanation for this reverse reactivity. Ferrocenyl pyrylium salts of the type 5-5 have been prepared using a new route to ferrocenyl pyrylium from cyclomanganated chalcones and ferrocenylethyne. UV-visible and electrochemical properties of the pyrylium salts have been investigated. The ferrocenyl pyrylium salt (5-5) was obtained by the oxidation of [2-ferrocenyl-4,6-diphenyl-ɳ₅]-pyranyltricarbonylmanganese (5-6). The crystal structure of 5-6 was also determined.

text: Organomanganese compounds in organic synthesis This thesis describes the preparation and reactions of some cyclomanganated chalcones, dienones and aryl ketones. Investigation has previously been undertaken into the reaction of cyclomanganated chalcones and dienones with alkynes to give both pyranyl and cycloheptadienyl Mn(CO)₃ complexes. In the current study, the reaction was further investigated with a cyclomanganated dienone derived from a cyclic ketone which gave only the (pyranyl)Mn(CO)₃ complex (2-6) and not the cycloheptadienyl product as consistent with a mechanism previously proposed. Also extended in the current study was previous work involving the methylmanganese pentacarbonyl-mediated transformation of enynes to cyclopropanated bicyclic compounds and cyclopentanes bearing an exocyclic double bond. In the current study, benzylmanganese pentacarbonyl was used instead of methylmanganese pentacarbonyl under similar conditions. In the current study however, the type of product that formed in diethyl ether (3-4) was the one dominant in acetonitrile in the MeMn(CO)₅ study, and that formed in acetonitrile (3-5) was the dominant product type in diethyl ether (3-4). There was no apparent explanation for this reverse reactivity. Ferrocenyl pyrylium salts of the type 5-5 have been prepared using a new route to ferrocenyl pyrylium from cyclomanganated chalcones and ferrocenylethyne. UV-visible and electrochemical properties of the pyrylium salts have been investigated. The ferrocenyl pyrylium salt (5-5) was obtained by the oxidation of [2-ferrocenyl-4,6-diphenyl-ɳ₅]-pyranyltricarbonylmanganese (5-6). The crystal structure of 5-6 was also determined.

year: 2009

title: Household credit to the poor and its impact on child schooling in peri-urban areas, Vietnam

authors: Doan, Tinh Thanh

subjects: school enrolment

abstract: This paper uses a novelty dataset of poor households in peri-urban areas in Vietnam to estimate impacts of small loans on child schooling. The Probit and Negative Binomial model estimates roughly indicate no strong evidence of the effect, especially of informal credit. Formal credit is likely to have positive impacts on child schooling, but its effect is not strong enough to be conclusive. The paper suggests that to obtain the target of sustainable poverty reduction, easing access to formal credit sources as well as exempting tuition and other school fees are necessary to keep poor children at schools longer.

text: Household credit to the poor and its impact on child schooling in peri-urban areas, Vietnam This paper uses a novelty dataset of poor households in peri-urban areas in Vietnam to estimate impacts of small loans on child schooling. The Probit and Negative Binomial model estimates roughly indicate no strong evidence of the effect, especially of informal credit. Formal credit is likely to have positive impacts on child schooling, but its effect is not strong enough to be conclusive. The paper suggests that to obtain the target of sustainable poverty reduction, easing access to formal credit sources as well as exempting tuition and other school fees are necessary to keep poor children at schools longer.

year: 2011-06

title: Do two rights fix a wrong? A study of employee and organizational responses to abusive supervision in New Zealand

authors: de Fluiter, Alida Jane

subjects: Abusive supervision

abstract: Organizational justice theories suggest that employees who are abused by their supervisor are likely to respond with lower job and personal outcomes. However, an under-explored area has been the influence of support perceptions. The present study suggests that perceived supervisor support (PSS) and perceived organizational support (POS) may moderate the influence of abusive supervision, and this was tested with three-way interactions. Data was collected from two samples: (1) 100 blue-collar workers in construction and (2) 218 random Maori employees from a variety of industries and professions. Structural equation modeling confirmed the unique constructs of the study measures towards abusive supervision and PSS and POS. Direct effects showed abusive supervision was significant and negative in both samples towards life satisfaction, job satisfaction, and organizational-based self-esteem (OBSE), and significant and positive in both samples towards turnover intentions, anxiety, depression, and insomnia. The results indicated that abusive supervision accounted for large amounts of variance towards all outcomes, with the exception of life satisfaction in study two (7%), and insomnia (8% in study one, and 4% in study two), ranging from 13%-32% variance. Significant three-way interactions were found for all outcomes except turnover intentions and insomnia. The three-way interaction towards life satisfaction in study one indicated that under abusive supervision, respondents with high PSS and high POS experienced the greatest levels of life satisfaction. Similar relationships were found toward depression (study one and two) and anxiety (study one), showing that respondents who experienced high abusive supervision, high PSS, and high POS had the lowest levels of negative mental health outcomes amongst all abused respondents. This suggested a potentially cumulative effect of multiple sources of support. Furthermore, towards job satisfaction in study two, findings show respondents with high abusive supervision and high POS reported the highest job satisfaction, irrespective of levels of PSS. A similar relationship was found toward OBSE in study two, suggesting that of the support variables examined, POS may have greater effect on outcomes, thereby supporting research of Dawley, Andrews and Bucklew (2008) who found POS to be the best predictor of organizational outcomes. Overall, this paper supports the notion that perceptions of support may moderate the influence of abusive supervision perceptions on employee’s work and personal outcomes. The findings show that while abusive supervision can play a dominant role on outcomes, this can be somewhat nullified by greater support from the organization. This has strong implications for firms dealing with problem supervisors, signaling the importance of establishing POS, and emphasizing that creating a supportive organization may be the first step to enabling employees to develop positive work and individual outcomes.

text: Do two rights fix a wrong? A study of employee and organizational responses to abusive supervision in New Zealand Organizational justice theories suggest that employees who are abused by their supervisor are likely to respond with lower job and personal outcomes. However, an under-explored area has been the influence of support perceptions. The present study suggests that perceived supervisor support (PSS) and perceived organizational support (POS) may moderate the influence of abusive supervision, and this was tested with three-way interactions. Data was collected from two samples: (1) 100 blue-collar workers in construction and (2) 218 random Maori employees from a variety of industries and professions. Structural equation modeling confirmed the unique constructs of the study measures towards abusive supervision and PSS and POS. Direct effects showed abusive supervision was significant and negative in both samples towards life satisfaction, job satisfaction, and organizational-based self-esteem (OBSE), and significant and positive in both samples towards turnover intentions, anxiety, depression, and insomnia. The results indicated that abusive supervision accounted for large amounts of variance towards all outcomes, with the exception of life satisfaction in study two (7%), and insomnia (8% in study one, and 4% in study two), ranging from 13%-32% variance. Significant three-way interactions were found for all outcomes except turnover intentions and insomnia. The three-way interaction towards life satisfaction in study one indicated that under abusive supervision, respondents with high PSS and high POS experienced the greatest levels of life satisfaction. Similar relationships were found toward depression (study one and two) and anxiety (study one), showing that respondents who experienced high abusive supervision, high PSS, and high POS had the lowest levels of negative mental health outcomes amongst all abused respondents. This suggested a potentially cumulative effect of multiple sources of support. Furthermore, towards job satisfaction in study two, findings show respondents with high abusive supervision and high POS reported the highest job satisfaction, irrespective of levels of PSS. A similar relationship was found toward OBSE in study two, suggesting that of the support variables examined, POS may have greater effect on outcomes, thereby supporting research of Dawley, Andrews and Bucklew (2008) who found POS to be the best predictor of organizational outcomes. Overall, this paper supports the notion that perceptions of support may moderate the influence of abusive supervision perceptions on employee’s work and personal outcomes. The findings show that while abusive supervision can play a dominant role on outcomes, this can be somewhat nullified by greater support from the organization. This has strong implications for firms dealing with problem supervisors, signaling the importance of establishing POS, and emphasizing that creating a supportive organization may be the first step to enabling employees to develop positive work and individual outcomes.

year: 2011