A new method of preparation and the properties (solubility, aggregation, spectralluminescent properties, singlet oxygen and photobleaching quantum yields) of non-metal 2,3,9,10,16,17,23,24-octacarboxyphthalocyanine are reported. The influence of ionization state on photophysicochemical properties of this dye is also presented.
Three new substituted manganese phthalocyanines (PcMns), wich are water-soluble, have been synthesized with good yields (70–80%) and high purity. Pyridiniummethyl- and cholinylsubstituted phthalocyanines have been obtained from the chloromethylsubstituted PcMns , while octacarboxysubstituted complex has been synthesized from metal-free octacarboxyphthalocyanine tetraanhydride. Compounds were characterized by elemental analysis and mass, IR and UV-vis spectroscopy. In general, coordination chemistry of the compounds studied is similar to this one of liposoluble PcMns but some new findings have been obtained. Three coordination forms — PcMn ( II ), PcMn ( III ) X ( X = Cl -, OAc -, …) and [ LPcMn ( III )]2 O ( L = Py , Et 3 N , …) have been obtained for all the new compounds. The equilibrium between three electronic isomers — Pc+• Mn ( I ) × L , PcMn ( II ) × nL , (n = 1, 2) and Pc-• Mn ( III ) × 2 L has been observed in PcMn aqueous solutions upon the addition of organic bases L ( Py , Et 3 N , …).
Water solubility of phthalocyanines (Pcs) usually increases by the introduction of charged or carboxy substituents in the peripheral positions of the macrocycle. As a result, such structural changes influence their photophysical and photochemical properties as photosensitizers. Phthalocyanines substituted with four or eight terminal carboxyl groups and having in some cases additional eight positive charges (water soluble phthalocyanines) were studied in order to evaluate the spectroscopic and photophysical effects of these side residues on the chromophore properties. The quantum yield of singlet oxygen (1O2) generation, the triplet-triplet absorption, and the transient absorption spectra were measured and linked to the structure of the substituents. It was shown that charged substituents did not change the quantum yields of 1O2 generation but decrease its lifetimes. The introduction of the charged substituents not only increases the water solubility but also significantly changes absorption, fluorescence, and transient absorption spectra of water soluble Pcs.
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