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Template-Directed Synthesis of One-Monomer-Thick Two-Dimensional Polymers Made of Cucurbit[6]uril

초록/요약

Synthesis of two-dimensional (2D) polymers on surface is an attractive strategy for the fabrication of nanoscale devices. Although numerous approaches have been reported over the last several decades, the synthesis of one-monomer-thick, covalently bonded 2D polymers with a long-range-ordered internal structure has yet to be achieved. This thesis describes the synthesis and characterization of one-monomer-thick 2D polymers made of cucurbit[n]uril (CB[n]), a family of synthetic molecules comprising n glycoluril units. The CB[n] based 2D polymers were synthesized on an atomically flat template-stripped gold (TSG) surface via the cross metathesis of (allyloxy)12cucurbit[6]uril (AOCB[6]) which consists of a rigid disk-shaped host molecule with twelve polymerizable allyl groups at the periphery. To synthesize one-monomer-thick 2D polymers, well-ordered an ammonium-terminated self-assembled monolayer (SAM) was prepared on a TSG substrate. An adlayer of AOCB[6] formed through hydrogen bonding and charge-dipole interaction between the carbonyl portal of AOCB[6] and the terminal ammonium group on the SAM. Polymerization of the AOCB[6] adlyaer was carried out using the Grubbs’ catalyst and the resulting polymers were transferred to other substrates and characterized using various techniques including fluorescence spectroscopy and transmission electron microscopy, atomic force microscopy, and scanning tunneling microscopy. Interestingly, this 2D polymer shows a sheet-like structure and one-monomer-thick with several micrometer lateral dimensions. CB[n] has a hydrophobic hollow cavity that is accessible through two identical carbonyl portals and thus through strong host-guest interactions such 2D polymers become more attractive for various applications such as functionalized membrane, sensor, and others.

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목차

Abstract i
Contents iii
List of Figures and Schemes v

1. General Introduction
1.1. Supramolecular chemistry 1
1.2. Cucurbiturils 5
1.3. Two-dimensional polymers 12
1.4. Research goals and thesis organization 14

2. Results and Discussions
2.1. Design and synthesis of compounds for allyloxy CB[6] based two-dimensional polymers 16
2.1.1. Preparation of template-stripped gold surface (TSGs) 16
2.1.2. Synthesis of compounds for allyloxy CB[6] based two-dimensional polymers 19
2.2. Synthesis of allyloxy CB[6] based two-dimensional polymers 19
2.2.1. Preparation of 10-aminodecanethiol SAM on TSGs 22
2.2.2. Preparation of AOCB[6] adlayer on ADT SAM 22
2.2.3. Adsorption property of AOCB[6] adlayer 22
2.2.4. Polymerization of AOCB[6] adlayer on ADT SAM 25
2.3. Characterization of allyloxy CB[6] based two-dimensional polymers 25
2.3.1. Stamping of allyloxy CB[6] based two-dimensional polymers 25
2.3.2. TEM study of allyloxy CB[6] based two-dimensional polymers 27
2.3.3. AFM study of allyloxy CB[6] based two-dimensional polymers 27
2.3.4. Internal structure characterization of allyloxy CB[6] based two-dimensional polymers with gold nanoparticles 27
2.3.5. STM study of allyloxy CB[6] based two-dimensional polymers 31
2.3.6. Surface modification of allyloxy CB[6] based two-dimensional polymers with fluorescein isothiocyanate (FITC)-spermidine 33
2.3.7. PMMA-mediated transfer of allyloxy CB[6] based two-dimensional polymer 35
2.3.8. Characterization of PMMA-mediated transferred allyloxy CB[6] based two-dimensional polymer 38
2.3.9. Isolation experiment of allyloxy CB[6] based two-dimensional polymers 38

3. Conclusion 43

4. Experimental Sections 44

5. References 49

Summary (in Korean) 53
Curriculum Vitae 55

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