81 |
LUMINESCENT TRANSITION METAL COMPLEXES BASED ON N-HETEROCYCLIC AND N^C-CHELATE 4-COORDINATE ORGANOBORYL LIGANDSWang, NAN 07 January 2013 (has links)
The objective of this thesis is to examine the photophysical and structural properties of Ru(II)/Re(I) based bimetallic complexes based on p-[N-2-(2’-pyridyl)benzimidazolyl]-[N-2-(2’-pyridyl)indolyl]-benzene (L1) ligand, as well as the photophysical and photochemical properties of N^C-chelate 4-coordinate organoboron compounds that contain a metal acetylide group.
Ligand L1 was synthesized and fully characterized. Due to the incorporation of two distinct chelating sites, an N^N-chelate site and an N^C-chelate site, L1 has been found to be very effective in selective binding to two different metal ions.
Two new heterobimetallic complexes Ru(II)-Pt(II) and Ru(II)-Pd(II) using L1 as the bridging ligand were prepared and fully characterized. All Ru(II)-containing complexes have been found to be luminescent. The Pt(II) unit appears to enhance phosphorescent efficiency of the Ru(II) unit while the Pd(II) unit has little influence.
Using L1 as the bridging unit, two new Re(I) based heterobimetallic complexes Re(I)-Pt(II) and Re(I)-Pd(II) were also successfully synthesized. Results indicate that there is communication between the two different metal centers. The preliminary results indicated that the mononuclear Re(I) complex based on L1 is a promising candidate for the electrocatalytic CO2 reduction.
Pd(II) and Pt(II) complexes were synthesized with an atropisomeric bis-pyridyl chelate ligand bis{3,3’-[N-Ph-2-(2’-py) indolyl]} (L4). To examine the potential use of the trans-chelate L4 ligand in oxidative coupling reactions catalyzed by Pd(II) compounds, acetoxylation of arenes by PhI(OAc)2 using PhI(OAc)2/L4 (2:1) as the catalyst was examined and found to accelerate the reaction, but lower the overall yield.
Finally, to examine the impact of metal ions on photochromic properties of N^C-chelate organoboron compounds, three metal acetylide compounds that contain a photo-active N^C-chelate BMes2 unit (B(ppy)Mes2) were prepared and fully characterized. The studies indicated that by taking advantage of different heavy metals the photoisomerization quantum efficiency of the boron chromophores can be readily tuned through the adjustment of 3LC state localized on the chelate backbone or the involvement of MLCT state in the lowest energy electronic transition. / Thesis (Ph.D, Chemistry) -- Queen's University, 2013-01-07 15:20:45.675
|
82 |
The electronic spectrum of copper dichlorideBarnes, Martin Paul January 1995 (has links)
No description available.
|
83 |
U.V. and X-ray preionised high-pressure COâ†2 lasers and line narrowing for spectroscopic studiesRaouf, Dayah Noori January 1987 (has links)
No description available.
|
84 |
Synthesis, structure and properties of copper(II) complexes and their ligandsOakley, Michael Andrew January 1995 (has links)
No description available.
|
85 |
The synthesis and reactions of some new cationic alkyne complexes of tungsten(II)Flower, Kevin R. January 1990 (has links)
No description available.
|
86 |
The influence of demography on European and future Armed ForcesStemmer, Ekkehard 06 1900 (has links)
Such demographic factors in Europe as low fertility rates, high life expectancy, and the restricted immigration policy have caused European societies to age rapidly and the population of Europe will dramatically decline over the next thirty years. In comparison to Europe, the trend of aging in developing counties, for example in the Middle East and Northern Africa, presents a stark contrast. Taking into account demographic trends like aging, global distribution of the population, and migration, Europe faces increasing geopolitical challenges in the future, based on the cleavages "north versus south," "rich versus poor," and "old versus young." From a domestic point of view of Continental Europe, the demographic factors are responsible not only for a declining workforce but also for increasing retirement rates. The consequences are a decreasing GDP and increasing social welfare costs. So, further development of European armed forces in an uncertain world has to take place in this tense financial situation. Taking the goals of the European Security Strategy into account and considering the necessity that the military capabilities have to be adapted to meet a new threat scenario, this thesis tries to illustrate why Europe has to intensify its efforts of European military integration, mindful of the limitation of demography and politics.
|
87 |
Reaksies van oorgangselementkarbeenkomplekse met stikstofnukleofiele22 October 2015 (has links)
M.Sc. (Chemistry) / Please refer to full text to view abstract
|
88 |
The effects of non-starch polysaccharides on the hydrolysis, gelatinisation and retrogradation of starchSommerville, Marion Don January 2000 (has links)
No description available.
|
89 |
The Middle School Transition in Private Schools: Student PerceptionsAtkinson, Eileen 28 April 2010 (has links)
Abstract THE MIDDLE SCHOOL TRANSITION IN PRIVATE SCHOOLS: STUDENT PERCEPTIONS By Eileen Irby Atkinson, Ph.D. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Virginia Commonwealth University, 2010 Director: Cheryl Magill, Ph.D., Assistant Professor, Department of Educational Leadership Students transitioning into the middle school often experience difficulty adjusting to their new environment. During this transition, declines in academic motivation, academic achievement, and connectedness have been noted. Most research on this transition has taken place in public school settings. This research investigated the impact of the middle school transition in a private school setting. This study examined students’ perceptions of the middle school transition as it related to the connectedness students perceived to their new school, those individuals whom students perceived as most helpful during their transition, academic motivation and achievement following the transition, and perceived helpfulness of transition activities conducted by the school. In addition, the study examined significant differences of the transition experience based on gender and race. Five hundred and two private middle school students in 35 private schools in Virginia completed a paper and pencil survey in which they responded to 47 questions regarding their transition into middle school. It was found that students generally felt connected to middle school, and the number of extracurricular activities in which a student participated did not appear to correlate significantly with connectedness. Most new middle school students did not perceive their transition experience as difficult. Middle school teachers, parents and friends appeared to be the most helpful to students during their transition. As compared to elementary school, newly transitioned middle school students were more academically motivated, and academic achievement showed a slight improvement in middle school. Students reported that visits made to the middle school as an elementary student were most helpful to their transition, and that the summer orientation and tour were also found to be helpful. Males perceived parents, middle school teachers and elementary school counselors as more helpful to their transition than did females, who considered friends most helpful. Parents were perceived as most helpful to the transition by Asian students. Caucasians reported higher academic achievement in middle school than African American students, and African American students perceived their academic achievement as higher than that of Hispanic students. African American students, more than any of the other groups represented, believed that the information given to the middle school by the elementary school was very helpful to their transition. Native American students, and students identifying their race as “Other” felt that the assignment of an older middle school buddy was more helpful to the transition than did Caucasian or Hispanic students. In terms of the relative contribution of the variables to the prediction of ease of transition, the number of transition activities has the greatest influence, followed by level of support from others, perception of connectedness to middle school, and middle school academic performance.
|
90 |
Examining the impact of reforms on economic growth: The case of transition economiesZhupaj, Lorena January 2013 (has links)
This paper aims to investigate the impact of reforms on economic growth in a sample of transition economies of Central Eastern Europe, South Eastern Europe and Commonwealth of Independent States from 1989 until 2010. We employ a panel data methodology and run a Haussman test to distinguish between a fixed effect and a random effect model. In addition, we take into account the role of reform reversals and examine their contribution in the growth dynamics. Reform downgrades are very common since in some cases progress in reforms has been stalled or even reversed due to political instability, wars, economic crises, etc. We model the reforms downgrades following the previous work of Merlevede (2003) using a different methodology and extending our period of estimation. Furthermore, the relationship between other explanatory variables (i.e. initial conditions, fiscal balance) and growth is further explored in the empirical estimation. JEL Classification O57, P21 Keywords transition economies, reforms, reversal Author's e-mail lorena_zh@hotmail.com Supervisor's e-mail roman.horvath@gmail.com
|
Page generated in 0.1085 seconds