Thermodynamics of the dimerization of copper(II) Phthalocyanine-4,4',4'',4'''-tetrasulphonic acid

Blagrove, RJ; Gruen, L.C.

doi:10.1071/ch9730225

Cited by 19 publications

(9 citation statements)

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“…[168] The literature presents several interesting articles based on synthesis, characterization, and reactivity of phthalocyanines and metallophthalocyanines. [143][144][145][146][169][170][171][172][173][174][175][176][177][178][179][180][181][182] However, mainly in the last years, the studies about the application of these compounds in PDT have gained more emphasis. Aluminium phthalocyanine chloride is an example of a metallophthalocyanine with good preliminary results regarding applications in PDT.…”

Section: Phthalocyanines and Metallophthalocyaninesmentioning

confidence: 99%

Photodynamic Therapy: Porphyrins and Phthalocyanines as Photosensitizers

et al. 2008

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The present work is focussed on the principles of photodynamic therapy (PDT), emphasizing the photochemical mechanisms of reactive oxygen species formation and the consequent biochemical processes generated by the action of reactive oxygen species on various biological macromolecules and organelles. This paper also presents some of the most used photosensitizers, including Photofrin, and the new prototypes of photosensitizers, analysing their physicochemical and spectroscopic properties. At this point, the review discusses the therapeutic window of absorption of specific wavelengths involving first-and second-generation photosensitizers, as well as the principal light sources used in PDT. Additionally, the aggregation process, which consists in a phenomenon common to several photosensitizers, is studied. J-aggregates and H-aggregates are discussed, along with their spectroscopic effects. Most photosensitizers have a significant hydrophobic character; thus, the study of the types of aggregation in aqueous solvent is very relevant. Important aspects of the coordination chemistry of metalloporphyrins and metallophthalocyanines used as photosensitizers are also discussed. The state-of-the-art in PDT is evaluated, discussing recent articles in this area. Furthermore, macrocyclic photosensitizers, such as porphyrins and phthalocyanines, are specifically described. The present review is an important contribution, because PDT is one of the most auspicious advances in the therapy against cancer and other non-malignant diseases.

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Section: Phthalocyanines and Metallophthalocyaninesmentioning

confidence: 99%

Photodynamic Therapy: Porphyrins and Phthalocyanines as Photosensitizers

et al. 2008

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“…Calculation of aggregation parameters. We obtained variable results with simplified methods of determining monomer-dimer equilibrium constants, K,, and the respective monomer and dimer absorptivities, cM and cD (Blagrove and Green, 1972). Therefore, we chose to use a more complicated method but one which makes fewer assumptions for two state equilibria.…”

Section: Chemicalsmentioning

confidence: 99%

Biological Activities of Phthalocyanines—vi. Photooxidation of L‐tryptophan by Selectively Sulfonated Gallium Phthalocyanines: Singlet Oxygen Yields and Effect of Aggregation

Wagner

Ali

Langlois

et al. 1987

Photochem & Photobiology

112

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Abstract— The photosensitized oxidation of L‐tryptophan by gallium phthalocyanines sulfonated to different degrees is studied as a function of both substrate and sensitizer concentrations in water and 50% MeOH‐H2O solutions. The maximum quantum yield of singlet oxygen was found to be nearly 0.5 for all sulfonated gallium complexes. The effect of adding sulfonate groups in the phthalocyanine backbone is to change the tendency of dye molecules to dimerize or aggregate in a particular solvent. A shift in the chemical equilibrium away from the monomeric state, which occurs at high dye concentrations and at lower degrees of dye sulfonation, results in a reduced photochemical yield. The variation of quantum yields in different solvent systems and at several wavelengths is similarly accounted for by the fraction of light absorbed by the productive monomer state.

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“…The sulfonated aluminum phthalocyanines, AlPcS n ( n = 1−4), have attracted much attention recently due to their potential uses in various biological applications. , In biological systems AlPcS n binds to various proteins and membranes, resulting in complex photophysical behavior , Phthalocyanines have been reported previously to display a strong tendency to form dimers and higher-order aggregates in water as a result of the propensity of the large hydrophobic skeleton to avoid contact with the aqueous medium. − Disaggregation is known to be facilitated by the addition of solvents such as methanol, ethanol, pyridine, or dimethyl sulfoxide or by incorporation into cationic micelles …”

Section: Introductionmentioning

confidence: 99%

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

et al. 1996

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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.

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Thermodynamics of the dimerization of copper(II) Phthalocyanine-4,4',4'',4'''-tetrasulphonic acid

Cited by 19 publications

References 0 publications

Photodynamic Therapy: Porphyrins and Phthalocyanines as Photosensitizers

Photodynamic Therapy: Porphyrins and Phthalocyanines as Photosensitizers

Biological Activities of Phthalocyanines—vi. Photooxidation of L‐tryptophan by Selectively Sulfonated Gallium Phthalocyanines: Singlet Oxygen Yields and Effect of Aggregation

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

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