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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Physicochemical Properties and Synthesis of Oligothiophene Macrocycles

Kaiser, Achim, January 2008 (has links)
Ulm, Univ., Diss., 2008.
2

Synthesis and characterization of polymers containing oligothiophenes

Ranieri, Nicola. January 2001 (has links) (PDF)
Mainz, Univ., Diss., 2001. / Computerdatei im Fernzugriff.
3

Synthesis and characterization of polymers containing oligothiophenes

Ranieri, Nicola. January 2001 (has links) (PDF)
Mainz, Univ., Diss., 2001. / Computerdatei im Fernzugriff.
4

Synthesis and characterization of polymers containing oligothiophenes

Ranieri, Nicola. January 2001 (has links) (PDF)
Mainz, University, Diss., 2001.
5

Synthese und Strukturierung von funktionalisierten Oligothiophenen

Allard, Sybille. January 2002 (has links) (PDF)
Mainz, Universiẗat, Diss., 2003.
6

Synthese und Strukturierung von funktionalisierten Oligothiophenen

Allard, Sybille. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2003--Mainz.
7

Neue Synthesestrategie zu alpha- und alpha,omega-substituierten Oligo- und Polythiophenen und deren Selbstorganisation

Ellinger, Stefan, January 2006 (has links)
Ulm, Univ. Diss., 2006.
8

Synthesis and characterization of fully pi-conjugated oligothiophene-based macrocycles

Fuhrmann, Gerda, January 2006 (has links)
Ulm, Univ. Diss., 2006.
9

The effects of crystallization on oligothiophene morphologies

Herrmann, Debra McGuire 06 January 2011 (has links)
Polythiophenes have shown potential as inexpensive organic semiconductors because of their charge mobility properties. Small changes in structures can change the electronic and optical properties. Because oligothiophenes demonstrate the same electronic properties, have better solubility, and are easier to purify without defects, oligothiophenes are used as models for the polythiophenes. X-ray diffraction is an accepted method for studying the structure and arrangement of atoms in oligothiophenes; however, XRD requires crystalline solids for analysis. Obtaining suitable crystals can be difficult. In this paper, two crystallization techniques, vapor diffusion and zone sublimation, and the results are discussed. Raman spectroscopy, a type of vibrational spectroscopy, will give information about the structure of a molecule and can act as the molecular fingerprint of the molecule. Raman spectroscopy does not require crystalline solids and provides a relatively fast analysis. If the Willets lab can characterize the oligothiophenes by Raman spectroscopy, demonstrate distinguishable spectra for the different morphologies, and correlate this to the X-ray diffraction data, Raman spectroscopy will be an easier and faster means for analyzing the oligothiophenes. / text
10

Synthesis and Characterization of an Oligothiophene-Ruthenium Complex and Synthesis and Optical Properties of Oligothiophene-Ruthenium Complexes Bound to CdSe Nanoparticles

Bair, Nathan A. 12 August 2010 (has links) (PDF)
Oligothiophenes are of increasing interest in organic based electronic devices in part due to their high electron and hole mobilities. In an organic photovoltaic (OPV) device, the electronic properties of oligothiophenes make them advantageous as charge transfer junctions. To serve as charge transfer junctions, oligothiophenes must be functionalized to bind to the donor and acceptor parts of the device. The donor and acceptor parts are different materials and the synthesis of asymmetric oligothiophenes is of great interest. Previous researchers in our lab synthesized four asymmetric oligothiophenes, two with two thiophene subunits and two with four. Each set of oligothiophenes contained a pair of constitutional isomers. Here we report the synthesis of another asymmetric oligothiophene, one with three thiophene subunits. This compound is functionalized with bipyridine to bind Ru(bpy)22+ and with phosphonic acid moieties to bind CdSe nanoparticles. The synthesis was carried out by bonding a phosphonic acid moiety to bithiophene and bipyridine to thiophene and then coupling the phosphate-bithiophene and thiophene-bipyridine. Standard Stille couplings were used for carbon-carbon bond formation. The resulting compounds have complex NMR spectra and overlapping Ru MLCT and π-π* transitions at 450 nm with molar extinction coefficient on the order of 3 x 105 M-1 cm-1. The thiophene fluorescence is quenched by Ru(bpy)22+. These optical properties compare closely with the previous compounds synthesized. Solar cells occupy significant attention in the media, politics and science for their promise of continual pollution-free energy. Quantum dots, metal complexes and organic compounds are all under research as viable replacements for expensive silicon solar cells. To test the efficacy of a light harvesting compound before constructing a solar cell, a model system is constructed to show electron transfer from the light harvester into an electron acceptor. We synthesized oligothiophenes and oligothiophene-ruthenium complexes and tested their ability to act as sensitizers and charge transfer junctions. To do this, they were bonded to CdSe nanoparticles and their optical properties were measured. Steady-state photoluminescence and time correlated single photon counting were used to observe the effects on fluorescence and fluorescence lifetime of the CdSe-oligothiophene and CdSe-oligothiophene-ruthenium complexes before and after binding. It was found that CdSe fluorescence was quenched when bound to an oligothiophene ruthenium complex, and that the fluorescence of the oligothiophene was quenched when bound to CdSe in the absence of ruthenium. The fluorescence lifetimes of the quenched species were shortened.

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