Abstract: The deprotonation of an amphiphilic porphyrin, meso-tetra (p-hydroxylphenyl)porphyrin with a hexadecyl chain(THPPH₂), has been observed by means of UV-Visspectroscopy in CTABmicellar solutions. With increasing of PHvalues, the Soret band shiftsfrom 424 nm to 441nm, and the four-Qbands (520 nm, 560 nm, 595nm, 655 nm) aredisappeared while two new Q-bands are appeared at 585 nm and 675 nm, which is similar tometal-porphyrin, means that the deprotonation of porphyrin takes place. Comparing withthe spectra in an other solutions, the spectral characteration of THPPH₂ in neutral and inbasic CTABsolutions is similar to that in CHCl₃ and basic aqueous solutions respectively,suggesting that the solubilizing location of THPPH₂ takes a change from inner to the outer of theCTABmicellars with the PHvalue of solutions increasing between 6.20 and 11.19.

Key words: Amphiphilic porphyrin, Deprotonation, Solubilizing location, CTAB micella