Honors College Theses

Publication Date



Chemistry (B.S.)

Document Type and Release Option

Thesis (open access)

Faculty Mentor

James LoBue


Photodynamic therapy(PDT) is a type of cancer treatment that utilizes photosensitive molecules that absorb photons and use that energy to create cytotoxic molecules. Porphyrins are photosensitive compounds that can be used selectively at the site of cancerous tumors. Their selectivity is due to the fact the porphyrins are generally not toxic in absence of light; in the presence of light, the drug will be activated to produce the cytotoxic molecule, singlet oxygen(1O2 ). 9,10 diphenyl anthracene(DPA) was used to simulate the cancer cells and monitor how effective the porphyrin was in creating 1O2, because DPA reacts with 1O2 form diphenyl anthracene-endoperoxide (DPA-EPO). The DPA and two studied porphyrins, meso-Tetra (2,3,4-trifluorophenyl) porphyrin and meso-Tetra (2,3,5,6-tetrafluorophenyl) porphyrin were dissolved in 1,4 dioxane. The solutions were photolyzed with a Coherent I90 Argon laser and absorbance spectra was measured at 15 minute time intervals for 90 minutes. Using these spectra, the reaction order and rate were found with respect to porphyrin and DPA. Carbon-13 NMR spectra was collected that provided critical evidence that DPA-EPO was formed in the photolyzed solution.