Free radicals (Chemistry)

Nitric acid can drive oxidation reactions of paraffins producing nitroparaffins and
other oxidation products. Presented here is a study on the aqueous liquid phase nitric
acid oxidation of paraffin oil supported on PTFE particles. The goals ofthis study
are:
1. To evaluate the effectiveness of nitric acid in removing paraffin oil from
PTFE particle surfaces.
2. To evaluate the effects of nitric acid driven reactions with paraffin oils
under varying reaction conditions.
3. To evaluate FTIR Diffuse Reflectance Spectroscopy, DRIFT, as a tool to
accomplish the quantitative analysis of this process. These goals have been achieved employing analysis by FTIR Diffuse Reflectance,
which provides a ready means of quantifying paraffin removal. Paraffin removal
generally increases with time, temperature and nitric acid concentration and can be
described by known kinetics including activation energy and region of unity
relationship between the log of the rate constant verses Hammett acidity function.

Aging is a process characterized by accumulated oxidative damage to DNA, proteins, and lipids,which leads to the gradual degeneration of cellular activity. Mitochondria play a central role in aging because they produce both cellular energy and oxidative stress. As resultof accumulated oxidative damage, mitochondria function decays, which leads to a cellular energy deficit and compromises cellular function. Iron is an essential nutrient reequired by mitodhondria to function optimally. It has been proved that iron supplementation increases the lifespan of several yeast strains, including superoxide dismutase mutants. We are interested in finding where the iron is going and what it might be doing that is beneficial to the cell. We have used Saccharomyces cerevisiae as our molecular model of aging. Our results indicate that the extra iron is being transported into the mitochoindria.

PTFE (Teflon) tape has been reported as an alternative to liquid perfluoroalkanes in fluorous phase-vanishing (PV) reactions. Previous research on PV-PTFE reactions found that PTFE tape has unique characteristics compared to liquid flourous phase screens, including reagent permeabilities that are altered by exposure to certain organic solvents. This study investigates these characteristics by observing the effects of solvent adsorption on the diffusion of bromine and dimethyl phthalate. The directionality of solute diffusion in PV-PTFE chemiluminescence was also studied. Literature on Teflon films and on PV reactions is utilized to explain how the structural and chemical features of PTFE tape influence its permeability, and how solvents alter this permeability. We use structural arguments to explain why chemically-identical bulk PTFE behaves differently from PTFE tape. By better understanding how PTFE tape functions in PV reactions, the method may be improved and its use expanded.

Phase-vanishing reactions are triphasic reactions that involve a reagent, a liquid perfluoroalkane, and a substrate. In a phase-vanishing reaction with PTFE (polytetrafluoroethylene) tape as the phase screen instead of a liquid perfluoroalkane, there is no limitation related to the density of a phase, and the denser phase can be in the top layer. Additionally, PTFE tape is inexpensive, easy to use, and reusable. In this work we qualitatively described PTFE tape's thickness, stretching characteristics, and permeability. We investigated the phase-vanishing PTFE method's usefulness both in known transformations and also in a novel nucleophile-assisting leaving group (NALG) reaction with menthol, thionyl bromide, and zirconium(IV) chloride. We successfully used PTFE tape as a phase screen in bromination, bromolactonization, esterification, chemiluminescence, and tandem bromination/esterification phase-vanishing reactions. We found that the PTFE tape is an effective phase screen and useful in performing a slow addition of a reagent.