• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 37
  • 12
  • 5
  • 4
  • 3
  • 2
  • 1
  • Tagged with
  • 76
  • 32
  • 15
  • 12
  • 10
  • 9
  • 8
  • 8
  • 8
  • 7
  • 7
  • 6
  • 6
  • 6
  • 5
  • 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.
11

Retention Characteristics of Water-Soluble Calixarene Modified Mobile Phases

Lowe, Christian T. January 1998 (has links)
No description available.
12

Part I: Solid State Studies of Larger Calixarenes : Part II: Synthesis and Characterization of Metallocalixarenes

Smith, Janna Marie 05 1900 (has links)
Calixarenes are a class of macrocyclic compounds that have garnered interest in large part because of their ability to form host-guest complexes with various types of molecules. For all of the studies of complex formation by calixarenes, most of the work to date has concentrated upon the smaller calixarenes, and little is understood about the relationship between the complexes formed when in solution and that observed in the solid state. The first part of the study, presented in Chapter 3, is of the solid-state properties of two of the larger calixarenes, and in comparison to other reported structures reveals patterns to the observed conformations both in the solid state and in solution. The formation of metal complexes has also been investigated and has focused extensively upon the metals as guests. Thus, the ability of the calixarenes to act as ligands in inorganic complexes has been virtually untapped, despite the polyoxo binding site they can easily provide, and very few metallocalixarenes have been reported. The second part of this study goes beyond the simple solid-state properties of such compounds, and involves the synthesis of several metallocalixarenes as part of a project directed at the functionalization of calixarenes with the components of a class of catalysts known to polymerize various olefins. These catalysts, commonly referred to as Ziegler-Natta catalysts, are introduced in Chapter 4. The new compounds presented here--three new aluminocalixarenes in Chapter 5 and a new titanocalixarene in Chapter 6--were synthesized so as to contain some of the same components observed in several of the other catalysts. These new compounds have been characterized crystallographically as well as through proton and multinuclear NMR, and observed conformational patterns are discussed.
13

Synthetic stratergies towards a diureidocalix[4]arene / Synthetic strategies towards a diureidocalix[4]arene

Reid, Suazette N. 29 October 2004 (has links)
Self-organization is a common occurrence among molecules in nature and questions of how and why these molecules interact and come together by intermolecular forces has been under investigation by those interested in molecular recognition. Synthetic molecules able to mimic nature have become important in the area of supramolecular chemistry. Calixarenes are a group of molecules that is being investigated for their ability to self-assemble into dimeric capsules. Such capsules can be very useful for catalysis, molecular recognition and for encapsulation. The synthetic stratergies involved in the synthesis of a diureidocalix[4]arene is presented. In this case the taget molecule is a tetrapropylcalix[4]arene substituted on the upper rim with two urea groups separated by a hydrocarbon chain will be synthesized. This molecule can then be used to investigate its dimerization properties.
14

Solvent and Ionic Complexes of the Calix[6]arenes

Wolfgong, William J. 12 1900 (has links)
One of the more attractive attributes of calixarenes is their wide variety of possible conformations and hence cavity shapes. However, the flexibility that allows this long-range benefit gives rise to major synthetic challenges when working with the larger members of the family. O-alkylations have proven to be the most widely employed synthetic routes to "functionalization" of the calixarenes, and these have shown a dependence upon both solvent and the metal ions present. Surprisingly, there have been no structural data presented concerning the complexes between the simple unsubstituted calix[6]arenes and the metal ions of groups 1 and 2. The structures of four complexes, containing cesium, rubidium, and calcium are reported as determined by X-ray crystallography. The solution behavior of the complexes for both representative groups is also discussed, in particular with regard to conformational stabilization of the calix[6]arenes and the role of solvent upon this stabilization. These complexes are also investigated as starting materials for the selective functionalization of the calix[6]arenes.
15

Electrochemistry of calixarene derivatives : applications in electroanalysis and surface functionalisation

Pailleret, Alain January 2002 (has links)
No description available.
16

Structural supramolecular constructs of spheres and tubes

Heaven, Michael William, January 2006 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. 3 MPEG files (not linked from research.pdf file). Title from title screen of research.pdf file viewed on (Feb. 27, 2007). Vita. Includes bibliographical references.
17

Synthesis and characterization of HPLC stationary phases using 4-tert-butylcalix[n]arenes /

Hirschl, Rhonda Sue. January 1998 (has links)
Thesis (M.S.)--Youngstown State University, 1998. / Includes bibliographical references (leaves 120-122).
18

Retention characteristics of water-soluable calixarene modified mobile phases in HPLC /

Lowe, Christian T. January 1998 (has links)
Thesis (M.S.)--Youngstown State University, 1998. / Includes bibliographical references.
19

Synthetic stratergies [sic] towards a diureidocalix[4]arene

Reid, Suazette N. January 2004 (has links) (PDF)
Thesis (M.S.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2005. / Kubanek, Julia, Committee Member ; Collard, David, Committee Member ; Shuker, Suzanne, Committee Chair. Includes bibliographical references.
20

Complexation studies of calixnaphthalenes and hexahomotrioxacalixnaphthalenes with [60] fullerene /

Mizyed, Shehadeh A., January 2001 (has links)
Thesis (Ph.D.)--Memorial University of Newfoundland, 2002. / Bibliography: leaves 161-173.

Page generated in 0.0436 seconds