Polycyclic Aromatic Hydrocarbon (PAH)-Based Conjugated Macrocycles and Polymers For Electronic Applications

Due to the high tendency to form π-stacked ordered phases, polycyclic aromatic hydrocarbons (PAHs) are attractive building blocks for the assembly of conjugated systems for electronic applications. The body of this dissertation focuses on the synthesis, structure-property and device studies of PAH-based conjugated systems, including PAH–based conjugated macrocycles, conjugated polymers and conjugated foldamers. Novel PAH-based conjugated macrocycles have been developed for electronic applications. Specifically, two imine-based shape-persistent macrocycles containing triphenylene building blocks have been synthesized. Their stable conformations are predicted by quantum mechanical calculations and confirmed by 2D NOESY NMR measurements. Compared to their corresponding building block PAHs, the macrocycles (12 and 13) show a higher propensity for solution self-assembly due to their stronger π-π stacking interactions and form micro-objects which exhibit enhanced conductivity after doping. While both macrocycles have identical molecular geometries and very similar structures, their solution self-assemblies lead to micro-objects with very different shapes. The special properties of PAH-derivatives have been utilized for the development of novel conjugated donor-acceptor (D-A) polymers for solar cell applications. A new PAH-based imide-functionalized naphthodithiophene (INDT) building block has been designed and synthesized. D-A conjugated polymers containing INDT as the acceptor unit and a 2,2'-bithiophene with varied substituents as the donor unit have been prepared. The bandgaps of these polymers depend strongly on the dihedral angle of the 2,2'-bithiophene unit. The 3,3'-dialkoxy substitution (polymers 41/42) leads to near planar bithiophene conformation due to the well-known S--O short contact, while the 3,3'-dialkyl substitution (polymer 44) results in significant backbone twisting due to the steric effect. Consequently, polymers 41 and 42 show lower bandgaps of 1.82, 1.85 eV, respectively, while polymer 44 has a bandgap of 2.38 eV. Solar cells fabricated from polymer 42 give the best device performance with power conversion efficiencies as high as 2.45% in air without any thermal annealing treatment, indicating the promising potential of INDT-containing conjugated polymers for efficient solar cells. INDT-based D-A foldamers have been developed as materials with high charge-carrier mobilities. Three D-A conjugated polymers containing INDT as the acceptor unit and fused aromatic systems as donor units have been synthesized. Preliminary optical property studies indicate that polymers 50 and 51 might have folded backbone geometry. Polymer 50, having naphthodithiophene derivative as donor unit, shows exceptionally high hole mobility of 0.129 cm²V⁻¹s⁻¹, measured by SCLC method.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Chemistry (UMKC)

Grantor

University of Missouri--Kansas City,

Year dc:date.issued

2014

Author dc:creator

• Dutta, Tanmoy

Advisor dc:contributor.advisor

• Peng, Zhonghua, Ph. D.

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/10355/47455

OAI identifier oai:identifier

oai:mospace.umsystem.edu:10355/47455