A Simple Method to Assess Porphyrin Basicity Using Competition Studies

Researcher Information

Abstract

Competition studies of three freebase porphyrins (H2OEP, H2OETPP, and H2TPP) were carried to assess their basicities. These porphyrins were selected because they are a good representation of natural occurring ones. In each experiment, the resultant UV-vis spectra were obtained by mixing and analyzing two porphyrins in a double-sided cuvette in which one was protonated using either trifluoroacetic acid (TFA) or hydrochloric acid (HCl) while the other was kept as a freebase. After mixing, the two porphyrins “compete” available protons, thus the most basic of them will acquire most of the protons. By adjusting the ratios of dications and freebases we concluded that the H2TPP was preferentially protonated and hence more basic than H2OEP and H2OEPP. Computations studies were used to validate porphyrin basicity.

Faculty Sponsors

Dr. Maria Ballester, Dr. Victor Castro, Dr. Brian Van Hoozen

Project Type

Event

Location

Alvin Sherman Library

Start Date

4-5-2023 12:00 PM

End Date

4-6-2023 4:00 PM

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A Simple Method to Assess Porphyrin Basicity Using Competition Studies

Alvin Sherman Library

Competition studies of three freebase porphyrins (H2OEP, H2OETPP, and H2TPP) were carried to assess their basicities. These porphyrins were selected because they are a good representation of natural occurring ones. In each experiment, the resultant UV-vis spectra were obtained by mixing and analyzing two porphyrins in a double-sided cuvette in which one was protonated using either trifluoroacetic acid (TFA) or hydrochloric acid (HCl) while the other was kept as a freebase. After mixing, the two porphyrins “compete” available protons, thus the most basic of them will acquire most of the protons. By adjusting the ratios of dications and freebases we concluded that the H2TPP was preferentially protonated and hence more basic than H2OEP and H2OEPP. Computations studies were used to validate porphyrin basicity.