Abstract
Highly reactive oxygen species (hROS) cause oxidative stress that can lead to diseases such as cancer and cardiovascular diseases. This research explored one of the ways these species can be made in the body; through abstraction of hydrogen from water by phenyl radicals. The phenyl radicals can enter the body through medications such as benzoyl peroxide, which is commonly used to treat acne making this research of relevance in the medical community. In this research, p-fluorophenyl radicals (FPh) were generated from p-fluorophenylazoisobutyronitrile (FPAIN) by visible photolysis in the presence of varying amounts of water and 3-iodobenzotrifluoride (ArI). The p-fluorophenyl radicals competitively react with water to form fluorobenzene (FPhH) and with 3- iodobenzotrifluoride to form 4-fluoroiodobenzene (FPhI). The yield ratios of the products [FPhH]/[FPhI] can then be measured by integration of their 19F NMR peaks and plotted versus the reactant concentration ratios, [H2O]/[ArI] to give a linear correlation, the slope of which corresponds to the relative rate constant, kH/kI = 0.0192. The rate constant for iodine abstraction from ArI (kI =2.2x108 M-1 s-1) is known so the experimentally determined slope allows the determination of the rate constant for hydrogen abstraction from water (kH =7.5 x 106 M-1 s-1).
College
College of Science & Engineering
Department
Chemistry
Campus
Winona
First Advisor/Mentor
Thomas Nalli
Start Date
4-19-2023 1:00 PM
End Date
4-19-2023 2:00 PM
Presentation Type
Poster Session
Format of Presentation or Performance
In-Person
Session
2a=1pm-2pm
Poster Number
1
Determining the Rate Constant for Hydrogen Abstraction from Water by p-fluorophenyl radicals
Highly reactive oxygen species (hROS) cause oxidative stress that can lead to diseases such as cancer and cardiovascular diseases. This research explored one of the ways these species can be made in the body; through abstraction of hydrogen from water by phenyl radicals. The phenyl radicals can enter the body through medications such as benzoyl peroxide, which is commonly used to treat acne making this research of relevance in the medical community. In this research, p-fluorophenyl radicals (FPh) were generated from p-fluorophenylazoisobutyronitrile (FPAIN) by visible photolysis in the presence of varying amounts of water and 3-iodobenzotrifluoride (ArI). The p-fluorophenyl radicals competitively react with water to form fluorobenzene (FPhH) and with 3- iodobenzotrifluoride to form 4-fluoroiodobenzene (FPhI). The yield ratios of the products [FPhH]/[FPhI] can then be measured by integration of their 19F NMR peaks and plotted versus the reactant concentration ratios, [H2O]/[ArI] to give a linear correlation, the slope of which corresponds to the relative rate constant, kH/kI = 0.0192. The rate constant for iodine abstraction from ArI (kI =2.2x108 M-1 s-1) is known so the experimentally determined slope allows the determination of the rate constant for hydrogen abstraction from water (kH =7.5 x 106 M-1 s-1).
