The goal of this research is to calculate extinction coefficients of several types of meso-substituted porphyrins. Extinction coefficients demonstrate the amount of light a molecule could absorb at a certain wavelength. The higher the extinction coefficient value is, the larger amount of light that could be absorb at a specific wavelength, Serial dilutions of porphyrin samples were conducted with different solvents to acquire extinction coefficients. Different organic solvents were used to access the impact polarity has on the coefficients. Toluene, chloroform and dichloromethane were used because those solvents dissolved the porphyrins homogenously. The order of solvent polarity from greatest to lowest is chloroform, dichloromethane and toluene. Visible spectra were acquired for each dilution. Extinction coefficient were calculated at 420-nm, which is the characteristic soret band for porphyrin molecules. For tetra-tolyl porphyrin, the average molar absorptivity values are 31,384 M-1 cm-1, 35,550 M-1 cm-1 and 28,651 M-1 cm-1 in dichloromethane, chloroform and toluene respectively. These extinction coefficients will be used to extrapolate the concentration of porphyrins encapsulated in liposomes for use in PDT

Calculation of extinction coefficients for meso-substituted porphyrins in different solvents

253rd National Meeting (2017)

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