Date of Graduation

2016

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Chemistry

Committee Chair

Kung K. Wang

Committee Co-Chair

Jeffrey L Petersen

Committee Member

Brian V. Popp

Committee Member

Carsten Milsmann

Committee Member

Yon Rojanasakul

Abstract

A synthetic pathw ay o f preparing functionalized [9]cycloparaphenylene ([9]CPP) bearing three evenly spaced 5,8-dim ethyoxynaphth-l,4-diyl units and tw o m acrocyclic [6]CPP precursors has been developed. The key steps included the D iels-A ld er reaction betw een (E,E)-1,4-bis(4-brom ophenyl)- 1,3-butadiene and 1,4-benzoquinone followed by m ethylation to produce an L-shaped building block w ith tw o 4-brom ophenyl groups cis to each other exclusively, the nickel-m ediated hom ocoupling reactions to construct the m acrocyclic dim ers and trim ers, and m ild, efficient oxidative arom atization by 2,3- dichloro-5,6-dicyano- 1,4-benzoquinone (D D Q ) to furnish the functionalized [9]CPP. A synthetic pathw ay for constructing fused carbon nanohoops w ith the two nanohoops in nanotube-like connection has also been developed. The key interm ediate with all four 4-brom ophenyl groups cis to one another in an L-shaped building block was prepared by two consecutive D iels-A ld er reactions, followed by m ethylation. The Ni(cod)2 -m ediated hom ocoupling reactions produced the m olecules that contained either tw o hydrogenated [6]CPP, or tw o hydrogenated [9]CPPs fused through 1,4- dim ethoxybenzene m oieties and other bent and fused nanostructures with subunits o f differing sizes o f CPPs. The structure o f a fused carbon nanohoop containing two hydrogenated [6]CPP units was established by X -ray structure analysis and a stepw ise synthetic sequence. The structure o f a m olecule containing tw o fused carbon nanohoops com prised o f tw o hydrogenated [9]CPPs was also established by a sim ilar stepw ise synthesis. In addition, a synthetic sequence to a functionalized [10JCPP has also been established. This synthetic pathw ay is being explored for the construction o f fused carbon nanohoops containing tw o fully arom atized [10]CPPs.

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