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LuX_dis (final comments).pdf (22.48 MB)
ETD Abstract Container
Abstract Header
Design and Construction of Terpyridine-based Two-Dimensional and Three-Dimensional Supramolecular Architectures
Author Info
Lu, Xiaocun
Permalink:
http://rave.ohiolink.edu/etdc/view?acc_num=akron1375364176
Abstract Details
Year and Degree
2013, Doctor of Philosophy, University of Akron, Polymer Science.
Abstract
Supramolecular self-assembly focuses on the studies of weak interactions beyond molecules and construction of complicated, well-defined supramolecular architectures which widely exist in natural process and have been used in catalysis, chemical sensing and molecular electronics. Utilization of <tpy-M
II
-tpy> (M = metal) connectivity to construct specific shaped supramolecular architectures has been well-developed.
Bis
terpyridines possessing 60° and 120° directionality can readily form triangular and hexagonal metallomacrocycles with group 12 metals, such as: Zn(II) and Cd(II), respectively. The supramolecular rhomboidal architecture could also be formed through a multicomponent self-assembly utilizing a precise stoichiometric ratio (1:1:2) of
bis
terpyridines with 60° or 120° directionality and metal ions (Zn
2+
or Cd
2+
). However, the triangular construct, which is formed solely by
bis
terpyridine with 60° branching angle, could also be detected in the same solution. To further probe the self-sorted formation of a rhomboidal architecture, a
tris
terpyridine possessing three adjacent terpyridine units is used. Such
tris
terpyridine ligand can readily react with 60°-directed
bis
terpyridine ligands and metal ions (Zn
2+
or Cd
2+
) in the stoichiometric ratio (2:2:5) to quantitatively form a center-bridged, fused-triangular shaped, rhomboidal structure. A facile heteroleptic self-assembly of hexa
kis
terpyridine and
tris
terpyridine possessing 60° angles between the adjacent terpyridine moieties with stoichiometric amount of Zn
2+
ions (1:6:12) leads to the formation of supramolecular spoked wheel architecture in a 90% isolated yield, which is fully characterized by ESI-MS, NMR, and TEM imaging. When the central hexa
kis
terpyridine of the spoked wheel is replaced with two staggered
tris
terpyridine ligands possessing 120° angle between the adjacent terpyridine units, a three-dimensional, supramolecular, bicycle-like wheel structure is readily formed, in which two 120°-directed
tris
terpyridines serve as the hub and spokes and six 60°-based
tris
terpyridines locate outside as rims. Another analogous supramolecular spoked wheel can also be formed by further redesign of the core ligand. Two
tris
terpyridine ligands possessing 60° between the adjacent terpyridine units adopt a parallel-staggered conformation with the opposite orientations to replace the core hexaligand. Eight equivalent amount of such
tris
terpyridine ligands (two serving as core ligands; six as outer rim ligands) can readily react with twelve equivalence of metal ions (Zn
2+
or Cd
2+
) to form a supramolecular mandoline-shaped wheel structure, which contains two vertex-connected, centrally-bridged rhomboidal moieties at the concentration of > 15 mg·mL
-1
. When the concentration of the Cd
2+
-based mandoline-shaped structure is reduced, a quasi-tetrahedron structure possessing four
tris
terpyridine ligands and six Cd
2+
ions can be detected and it becomes the only self-assembly product when the concentration is below 0.5 mg·mL
-1
. The Zn
2+
analogue of the mandoline-shaped structure remains intact during the dilution and there is no quasi-tetrahedron structure detected in such supramolecular system.
Committee
George Newkome, Dr. (Advisor)
Chrys Wesdemiotis, Dr. (Committee Member)
Stephen Cheng, Dr. (Committee Member)
Li Jia, Dr. (Committee Member)
Kevin Cavicchi, Dr. (Committee Member)
Pages
174 p.
Subject Headings
Polymer Chemistry
Recommended Citations
Refworks
EndNote
RIS
Mendeley
Citations
Lu, X. (2013).
Design and Construction of Terpyridine-based Two-Dimensional and Three-Dimensional Supramolecular Architectures
[Doctoral dissertation, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1375364176
APA Style (7th edition)
Lu, Xiaocun.
Design and Construction of Terpyridine-based Two-Dimensional and Three-Dimensional Supramolecular Architectures.
2013. University of Akron, Doctoral dissertation.
OhioLINK Electronic Theses and Dissertations Center
, http://rave.ohiolink.edu/etdc/view?acc_num=akron1375364176.
MLA Style (8th edition)
Lu, Xiaocun. "Design and Construction of Terpyridine-based Two-Dimensional and Three-Dimensional Supramolecular Architectures." Doctoral dissertation, University of Akron, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1375364176
Chicago Manual of Style (17th edition)
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Document number:
akron1375364176
Download Count:
459
Copyright Info
© 2013, all rights reserved.
This open access ETD is published by University of Akron and OhioLINK.