• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • Tagged with
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Investigating the Application of N,N’-Disubstituted-1,8-Diamidonaphthalene as a Ligand in Transition Metal and Main Group Chemistry

Almalki, Nawal 05 July 2018 (has links)
This thesis focuses on the design and development of novel versatile diamido ligands for transition metal and main group element chemistry. The central concept of this work deal relied on the design of N, N'-disubstituted-1,8-diaminonaphthalene (H2RR’-DAN) as proligands to dianionic diamido ligand scaffolds. These ligands would then be employed for stabilization of main group element (e.g. Li, B, Al) and transition metal (e.g. Ti, Zn) compounds.
2

Applications of N,N'-Disubstituted-1,8-Diaminonaphthalene as a Scaffold to Support Group 13 Compounds, Carbenes and Pd(II) Carbene Complexes

Lee, Sojung January 2017 (has links)
This work is mainly concentrated on the development of new versatile ligand based on N,N’-disubstituted-1,8-diaminonaphthalene (1,8-DAN) for main group chemistry. Therefore, our initial efforts were made on the design of new ligand scaffold by using 1,8-DAN. Following that, new ligand family supported by 1,8-DAN was applied as ligands to main group elements (B, Al, In, Ga, and C). Furthermore, six-membered ring carbenes which are derived from the reaction between N,N’-disubstituted-1,8-diaminonaphthalene and carbon are also investigated. In addition, the stable carbenes were implied as a new ligand system for palladium, leading to the formation of metal ligand complexes. Therefore, the synthesis and reactivity of these complexes are also reported. Chapter I gives an explanation on the basic concepts in terms of the ligand designs and reports the reasons why N,N’-disubstituted-1,8-diaminonaphthalene has been chosen as the framework of for these ligands. Chapter II presents the approach to synthesize ligands depending on the substitution. Regarding this, three methods were successfully used: reductive amination, application of acyl halide followed by reduction, and copper catalyzed C-N coupling reactions. Chapter III describes the reactions between the N,N’-disubstituted-1,8-diaminonaphthalene and main group elements B, Al, Ga, and In in 13 group. In this chapter, a variety of mononuclear and dinuclear complexes are investigated and fully characterized. Furthermore, some computational studies are also reported for the comparison with experimental results. Chapter IV deals with new ligand family, carbene, which is derived from N,N’-disubstituted-1,8-diaminonaphthalene. Therefore, not only fundamental concepts for the NHC (N-heterocyclic carbene) are discussed but also synthetic pathways are introduced. Moreover, interesting features of free carbene are presented as well. Chapter V reports the potential of this new carbene ligand family as ligands for transition metal compound, especially, Pd(II) compounds. Several different pathways for synthesizing the desired metal carbene complexes are presented.
3

Spectrofluorimetric Determination Of Organic And Inorganic Selenium In Vitamin Supplements After Cloud Point Extraction

Maden, Mervegul 01 October 2010 (has links) (PDF)
Selenium is a trace and essential element for good health but required only in very narrow range. Hence, determination of selenium in trace level in any matrix related with human health is important. A preconcentration method is performed to obtain a low detection limit for analyte. In this study, the methodology of cloud point extraction (CPE) was used as the preconcentration method for speciation of selenium in vitamin tablets. Non-ionic surfactant Triton X-114 and a fluorimetric ligand, 2,3- diaminonaphtalene (DAN) were used for the extraction of trace levels of organic and inorganic selenium species as a prior step to their determination by spectrofluorimetry. The aqueous solutions of nonionic and zwitterionic surfactant materials become cloudy when temperature reaches the cloud point temperature and analyte collapses with surface active material. The volume of surfactant rich phase is smaller than the solution volume and by this way high preconcentration factor was obtained. Optimization of the CPE parameters affecting complexation and phase separation was performed. Standard addition method was used in the quantitative measurements. Spectrofluorimetric determination of selenium was done using excitation and emission wavelegths of 380 nm end 570 nm respectively. The detection limit, established as 3s /slope where s is the standard deviation of 12 measurements of 0.02 mg/L Se-DAN complex after 10 fold preconcentration was 2.3 &micro / g/L. Accuracy of the method was checked using EnviroMat Waste Water, EU-L-2 as SRM and the result was in good agreement with certified value.Besides, selenium rich vegetables (dill, watercress herb and garlic) were grown in a pot at a controlled atmosphere.Selenium in plants (dill, watercress gerb and garlic), both control and enriched groups was determined by ICP-MS.

Page generated in 0.0724 seconds