The synthesis, characterization and an evaluation of the physical properties including infrared, UV-Vis absorption and fluorescence spectra, quantum yields and thermal stability of a variety of 2,5- and 2,6-diethynylypyridine based organic and Pt(II)-$ sigma$-acetylide monomers, oligomers and polymers, are reported. Quaternization of the pyridine-nitrogen in these compounds via solution nucleophilic substitution reactions with methyl iodide and methyl triflate yield stable pyridinium analogs. The introduction of positive charge into the backbone by this simple solution chemistry has a significant effect on the $ pi$-electron delocalization. For example, quaternization of the pyridine-nitrogen is accompanied by strong red-shifts in the UV-Vis absorption spectra. The latter is indicative of enhanced $ pi$-electron delocalization along the backbone upon quaternization. These compounds exhibit strong fluorescence, with quantum yields of 0.015 to 0.058 for the monomers, and 0.060 to 0.223 for the polymers. Quaternization is also observed to enhance fluorescence intensities and quantum efficiencies. These polymers are insulators in the ground state, however, upon doping with iodine exhibit semiconducting behavior. The $ pi$-electron delocalization is maintained through Pt(II) centers in the organometallic polymers, and similar effects of quaternization are observed in these highly soluble polymers.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.23386 |
| Date | January 1995 |
| Creators | Bunten, Kevin Andreas |
| Contributors | Kakkar, Ashok (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001485887, proquestno: MM12166, Theses scanned by UMI/ProQuest. |
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