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 (Φ_SO) 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.