Photophysical Characterization of Sulfonated Aluminum Phthalocyanines in a Cationic Reversed Micellar System

Abstract

The photophysics of sulfonated aluminum phthalocyanines, AlPcSn (n ) 0, 1, 2, 3, or 4), in cationic reversed micelles of benzyldimethyl-n-hexadecylammonium chloride (BHDC) have been investigated. Absorption and steady-state fluorescence emission spectroscopy indicate that only the di-and trisulfonated derivatives are essentially monomeric. Consequently, the triplet-state properties of only these nonaggregated phthalocyanines were investigated. Both derivatives exhibited enhanced intersystem crossing in this medium compared to homogeneous environments, yet the singlet oxygen quantum yields were found to be comparable to those obtained in homogeneous solutions. Time-resolved fluorescence emission studies yielded decays which were best fitted by a decay time distribution analysis rather than the more commonly used sum of exponentials model. The distributions were seen to broaden with increasing water concentration. The distribution of AlPcS n in the reversed micelles, which appears to be strongly influenced by the extent of sulfonation and the environment within the reversed micelle, is discussed.

Phthalocyanine photophysics and photosensitizer efficiency on human embryonic lung fibroblasts

“…Equation (2) is a modification of Gradyusho's equation, f f f t = 1 [19] and was modified by Gouterman [20]. The f t values appearing in Table 1 were calculated utilizing a f ic of 0.16 taken from Dhami et al [21] for an aluminum phthalocyanine disulfonate species in methanol. Much of the data seen in Table 1 was recently reported as part of a larger study involving phthalocyanine, porphyrin, benzochlorin, and purpurin photosensitizers [22].…”

Ultrafast Dynamics of Metal Complexes of Tetrasulfonated Phthalocyanines at Biological Interfaces: Comparison between Photochemistry in Solutions, Films, and Noncancerous and Cancerous Human Breast Tissues

“…75 It has been suggested that binding of tetrasulfonated metallophthalocyanines to phospholipid membranes is determined primarily by metal−phosphate coordination. 76 The hydrophilic or lipophilic property of the photosensitizers is related to their water solubility, which controls aggregation properties, and singlet oxygen production efficiency. Among the hydrophilic photosensitizers, anionic derivatives with sulfo substituents (Figure 1) such as AlPcS 4 are one of the best targets for a new generation of photosensitizers.…”

Oncologic photodynamic diagnosis and therapy: confocal Raman/fluorescence imaging of metal phthalocyanines in human breast cancer tissue in vitro

“…20,21 Studies have also demonstrated that a water-soluble tetrasubstituted cationic aluminum phthalocyanine (AlPcN(4)) efficiently bound to phospholipid membranes behaved similar to anionic tetrasulfonated aluminum and zinc phthalocyanine complexes. 22 Thus, the binding of tetrasulfonated metallophthalocyanines to phospholipid membranes has been suggested to be primarily determined through metal-phosphate coordination. 22 Among the hydrophilic photosensitizers, anionic derivatives of metal complexes of phthalocyanines with sulpho substituents, such as zinc tetrasulfonated phthalocyanine (ZnPcS 4 ) or AlPcS 4 , are some of the best targets for the generation of novel photosensitizers.…”

“…22 Thus, the binding of tetrasulfonated metallophthalocyanines to phospholipid membranes has been suggested to be primarily determined through metal-phosphate coordination. 22 Among the hydrophilic photosensitizers, anionic derivatives of metal complexes of phthalocyanines with sulpho substituents, such as zinc tetrasulfonated phthalocyanine (ZnPcS 4 ) or AlPcS 4 , are some of the best targets for the generation of novel photosensitizers. Metal phthalocyanines have become popular in PDT since Ben-Hur 23 reported the anticancer properties of phthalocyanine aluminum chloride.…”