The Effect of Fluorinated Substitution of Meso Phenyl Porphyrins on Porphyrin Basicity
Abstract
The purpose of this study was to determine the effects of fluorinated substitution of meso phenyl porphyrins on porphyrin basicity. The protonation of meso-Tetra(2,3,4-trifluoromethylphenyl) porphyrin (TF) and meso-Tetra(pentafluorophenyl) porphyrin (PF) will be studied through UV vis spectroscopy. Protonation is achieved by titration of each porphyrin in toluene with trifluoroacetic acid (TFA). The presence of a wavelength shift from the free base Soret to the protonated Soret will indicate the formation of a dication. The data from the UV spectra will be used to calculate the pKa values associated with each porphyrin. Based on the results, the average pKa for TF upon protonation was 2.07, while the average pKa for PF was 1.36 over four trials. A greater acidic value for PF was indicated from these results. In addition, a significant increase in the amount of acid added was noted during the protonation of PF when compared to the amount of acid needed for TF. This could indicate a correlation between the fluorinated position in the porphyrin and the formation of dication.
Faculty Sponsors
Dr. Maria Ballester, Dr. Victor Castro
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-6-2022 12:00 PM
End Date
4-7-2022 5:00 PM
The Effect of Fluorinated Substitution of Meso Phenyl Porphyrins on Porphyrin Basicity
Alvin Sherman Library
The purpose of this study was to determine the effects of fluorinated substitution of meso phenyl porphyrins on porphyrin basicity. The protonation of meso-Tetra(2,3,4-trifluoromethylphenyl) porphyrin (TF) and meso-Tetra(pentafluorophenyl) porphyrin (PF) will be studied through UV vis spectroscopy. Protonation is achieved by titration of each porphyrin in toluene with trifluoroacetic acid (TFA). The presence of a wavelength shift from the free base Soret to the protonated Soret will indicate the formation of a dication. The data from the UV spectra will be used to calculate the pKa values associated with each porphyrin. Based on the results, the average pKa for TF upon protonation was 2.07, while the average pKa for PF was 1.36 over four trials. A greater acidic value for PF was indicated from these results. In addition, a significant increase in the amount of acid added was noted during the protonation of PF when compared to the amount of acid needed for TF. This could indicate a correlation between the fluorinated position in the porphyrin and the formation of dication.
