Emissive Organic Radicals Substituted by Phosphorus-Containing Moities: Applications as oled materials
Thornton, Ragene A.
OLEDs are organic light emitting diodes, meaning that the emitted light is produced by organic molecules rather than solid-state materials used in LEDs. Typical OLEDs undergo emission events via closed shell systems. Radicals are considered “open shell” systems due to their lack of paired electrons. The maximum internal quantum efficiency (IQE) of an open system is 100% because the presence of only doublet states removes conflict with competing electronic states. This is significantly more efficient than the expected 25% IQE seen from fluorescence events in closed shell systems. The radical of interest in this research is tris (2,4,6-trichlorophenyl) methyl or TTM. The goal of the research at hand is to explore the effects of the introduction of pnictogen heteroles into the TTM radical system. Heteroles display attractive optoelectronic applications in organic electronic devices like OLEDs, organic field-effect transistors, and organo-photovoltaics. Carbazole is a heterole that has been at the forefront of OLED chemistry; expansion of research to the rest of the pnictogen group is significantly rarer. The production and analysis of the various heteroradicals should tell us whether the wavelength of the molecule could be tuned, if the quantum yield be adjusted, and if the stability of these molecules be improved. Due to the prevalence of carbazole in OLED systems, exploration of other pnictogen atoms could prove to be groundbreaking. There was success when the cationic form of TTM was used as the replacement for the TTM radical; although there was success, the goal of the research was not fulfilled because the product produced did not contain a radical anywhere throughout the molecule.
Dibenzophosphle, Phosphine, Phospholide
Thornton, R. (2019). <i>Emissive organic radicals substituted by phosphorus-containing moities: Applications as OLED materials</i> (Unpublished thesis). Texas State University, San Marcos, Texas.