Deprotonation of meso-tetra(p-hydroxylphenyl) porphyrin with a hexadecyl chain in CTAB micellar microenvironment

The deprotonation of an amphiphilic porphyrin, meso-tetra (p-hydroxylphenyl)-porphyrin with a hexadecyl chain (THPPH₂), has been observed by means of UV-Vis spectroscopy in CTAB micellar solutions. With increasing of pH values, the Soret band shifts from 424 nm to 441 nm, and the four-Q bands (520 nm, 560 nm, 595 nm, 655 nm) are disappeared while two new Q-bands are appeared at 585 nm and 675 nm, which is similar to metal-porphyrin, means that the deprotonation of porphyrin takes place. Comparing with the spectra in an other solutions, the spectral characteration of THPPH₂ in neutral and in basic CTAB solutions 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 the CTAB micellars with the pH value of solutions increasing between 6.20 and 11.19.