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Title: | Part I: Rapid Synthesis of Dendrimers by an Orthogonal Coupling Strategy. Part II: Design, Synthesis, and Characterization of Hydrogen-Bond Mediated Self-Assembling Dendrimers |
Author(s): | Zeng, Fanwen |
Doctoral Committee Chair(s): | Zimmerman, Steven C. |
Department / Program: | Chemistry |
Discipline: | Chemistry |
Degree Granting Institution: | University of Illinois at Urbana-Champaign |
Degree: | Ph.D. |
Genre: | Dissertation |
Subject(s): | Chemistry, Organic
Chemistry, Polymer |
Abstract: | Part I. Layered dendrimers were rapidly synthesized using an orthogonal coupling strategy. Fourth generation dendron 71 was prepared in four steps by sequential use of two AB$\sb2$ building blocks 66 and 67 under Mitsunobu esterification and Sonogashira coupling conditions. Further accelerated growth was achieved by merging the orthogonal coupling strategy with Frechet's branched-monomer approach. Thus, sixth generation dendron 81, with molecular formula $\rm C\sb{1292}H\sb{1369}IO\sb{242}$ and a molecular weight of 20897 amu, was synthesized in just three steps from the corresponding AB$\sb4$ monomers 72 and 73. In comparison to the most efficient dendrimer synthesis available, the orthogonal coupling strategy halves the number of synthetic steps needed by obviating protection-deprotection and activation chemistry. Part II. Discrete aggregates with a size in the nano-scale were formed by the hydrogen-bond mediated self-assembly of dendritic macromolecules. Several hydrogen bonding units were investigated, including anthyridine and diaminodihydropyridine moieties that are complementary (AAA-DDD), and self-complementary isophthalic acid, and 6-aminonicotinic acid subunits. Among them, dendritic tetraacids 189a-d were shown to self-assemble in a generation-dependent manner. The lower generation tetraacid 189a prefers to form a series of linear aggregates, while the higher generation tetraacids 189b-d tend to form a cyclic hexamer. The observation was supported by SEC dilution studies, VPO, and comparison with covalent models 208a-c. |
Issue Date: | 1997 |
Type: | Text |
Language: | English |
Description: | 220 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1997. |
URI: | http://hdl.handle.net/2142/77259 |
Other Identifier(s): | (UMI)AAI9737300 |
Date Available in IDEALS: | 2015-05-13 |
Date Deposited: | 1997 |
This item appears in the following Collection(s)
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Dissertations and Theses - Chemistry
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Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois