Author

Liu LiFollow

Author ORCID Identifier

https://orcid.org/0009-0009-2313-3061

Semester

Summer

Date of Graduation

2025

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Chemistry

Committee Chair

Kung Wang

Committee Co-Chair

Brian Popp

Committee Member

Brian Dolinar

Committee Member

Hacer Karatas Bristow

Committee Member

Jianhai Du

Abstract

The development of structurally defined carbon nanostructures has gained significant attention due to their unique electronic, optical, and mechanical properties. Cycloparaphenylenes (CPPs), also known as carbon nanohoops, and carbon nanobelts (CNBs) represent key molecular segments of carbon nanotubes (CNTs), offering a bottom-up approach to precise nanotube construction. This dissertation focuses on the synthesis, structural characterization, and functionalization of CPPs, as well as the development of novel synthetic pathways for CNBs. A series of functionalized CPPs, including [9]-, [12]-, [15]-, and [18]CPPs, were synthesized using a modular approach involving a Diels-Alder adduct formation followed by a Ni(cod)2/bpymediated macrocyclization reaction. The influence of precursor design, catalyst loading, and oxidative aromatization conditions on macrocyclization efficiency and product distribution was systematically investigated. Structural analysis via X-ray crystallography and spectroscopic techniques provided insights into the correlation between molecular conformation and reaction outcomes. In addition to CPP synthesis, novel methodologies for CNB construction were explored, addressing the challenges associated with strain energy and regioselective closure. Strategies leveraging sequential coupling reactions and oxidative cyclization provided access to structurally well-defined CNBs. The methodologies developed in this work not only enhance synthetic accessibility but also contribute to the broader understanding of carbon nanostructure formation. This research advances the field of nanocarbon chemistry by expanding synthetic approaches to CPPs and CNBs, offering new insights into their structural properties, and laying the groundwork for future applications in molecular electronics, optoelectronics, and nanomaterials science.

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