Nonionic omnisoluble photosensitizer reference material for the estimation of singlet oxygen quantum yield.

ABSTRACT

Meso-Tetrakis-(3,4,5-tris{2-[2-(2-methoxyethoxy)ethoxy]ethoxy}phenyl)porphyrin TEG12PH2 is reported as an 'omnisoluble' reference for singlet oxygen (1O2) generation quantum yield (ΦSO) estimation. TEG12PH2 is a highly soluble, nonionic compound possessing excellent 1O2 QY in a wide variety of common solvents, including water. TEG12PH2 was prepared on multigram scale by the 12-way O-alkylation of tetrakis(3,4,5-trihydroxyphenyl)porphyrin using 2-(2-(2-methoxyethoxy)ethoxy)ethyl 4-toluenesulfonate as a reaction solvent. The corresponding Zn(II) complex TEG12PZn was also prepared and studied. The 1O2 QYs of TEG12PH2 in the different solvents studied were found to be 0.86 (acetone), 0.59 (acetonitrile), 0.66 (chloroform), 0.85 (methanol), 0.45 (toluene) and 0.51 (water). TEG12PH2 can be considered a reliable and easy to implement omnisoluble reference compound for the estimation of the 1O2 generating activities of new materials, especially new porphyrinic compounds.