Synthesis, characterization and comparative studies on the photophysical and photochemical properties of peripherally and non-peripherally tetra-substituted zinc(II) phthalocyanines

Photochemical and photophysical properties of tetracarboxylic acid phthalocyanines from glycolic and lactic acids in homogeneous and micro heterogeneous media

Glycolic acid and lactic acid substituted zinc phthalocyanines were studied concerning their photophysical and photochemical properties in eight organic solvents (homogeneous medium) and in aqueous media with the presence of CTAB and PVP 360 surfactants. Solvent effects were investigated according to several physical solvent parameters, including studies that used more than one parameter at a time, such as the E_T(30) scale and the Lippet-Mataga equation. Computational studies were realized and was found in good agreement with experimental data indicating J-type dimers' formation through hydrogen bonds, which may not affect the spectroscopic properties. Fluorescence lifetimes were recorded using a time-correlated single-photon counting setup (TCSPC) technique. The direct method (analyzing the phosphorescence decay curves of singlet oxygen at 1270 nm) was employed to study singlet oxygen quantum yields. Phthalocyanine macrocycle with lactic acid substituent showed better solvation arrangement than the glycolic derivative, which can be explained based on the presence of the methyl group bonded to the chain. The water solvation of Pc's in the presence of cationic surfactant (CTAB) and biocompatible polymer PVP 360 increses the importance of this study for appliance in photodynamic therapy (PDT).

Helical Self-Assembly of Optically Active Glycoconjugated Phthalocyanine J-Aggregates

Four galactoconjugated zinc(II) phthalocyanines (Pcs) have been prepared and fully characterized. The carbohydrate-containing phthalonitrile precursors of the Pcs were synthesized through a copper-catalysed azide-alkyne cycloaddition (CuAAC). The Pcs show a remarkable aggregation behaviour in solution, depending on the nature of the solvent, the temperature and the substitution position on the phthalocyanine. Solvent-dependent CD-spectroscopy experiments show that these Pcs aggregate as chiral helices in solution. Crystal structure data of a phthalocyanine bearing two carbohydrate units substantiate the properties shown by CD spectroscopy. Furthermore, the 1,2,3-triazole moieties of the Pcs play a decisive role in the formation of supramolecular aggregates. The glycoconjugated zinc(II) phthalocyanines described here show molar extinction coefficients ϵ_max >10⁵  M^-1  cm^-1 and absorption maxima λ_max >680 nm, which make them attractive photosensitizers for Photodynamic Therapy (PDT).

Improved photodynamic activity of a dual phthalocyanine–ALA photosensitiser

The higher efficiency of the dual photosensitiser is a consequence of the generation of two photosensitisers inside the cell, which are activated concomitantly.

Investigation of the photophysical and photochemical properties of peripherally tetra-substituted water-soluble zwitterionic and cationic zinc(ii) phthalocyanines

4-{4-[N-((3-Dimethylamino)propyl)amide]phenoxy} substituted zinc(ii) phthalocyanine (2) and its water-soluble sulfobetaine (3), betaine (4) and N-oxide (5) containing zwitterionic and cationic (6) derivatives were synthesized for the first time in this study.

The synthesis and characterization of nonperipherally tetra terminal alkynyl substituted phthalocyanines and glycoconjugation via the click reaction

In order to obtain nonperipherally tetra terminal alkynyl substituted phthalocyanines (Pcs), new 3-pent-4-ynyloxy phthalonitrile (3) was prepared by the nucleophilic displacement reaction of 3-nitrophthalonitrile (1) and 4-pentyn-1-ol (2) and then cyclotetramerization was attained in the presence of zinc acetate, cobalt acetate, and/or DBU in n-pentanol without protection/deprotection. For the first time, the glycoconjugation of the nonperipherally tetra terminal alkynyl substituted zinc phthalocyanine (ZnPc) (6) can be easily achieved via the click reaction in a high yield. The electronic absorption spectrum of the glucopyranosyl substituted ZnPc (10) derivative showed a red-shifted Q band at 751 nm in dichloromethane due to the protonation of the meso nitrogens of the Pc macrocycle. Deacylation yielded ZnPc (11) bearing glucose substituents at nonperipheral positions with an improved water-solubility and non-aggregation in DMSO. The chemical structures of the new compounds were characterized by (1)H NMR, (13)C NMR, FT-IR, UV-Vis, mass spectrometry and elemental analysis. Moreover, the phthalonitrile compound was characterized using X-ray.

Novel axially disubstituted non-aggregated silicon phthalocyanines

This paper describes the synthesis, spectroscopic characterization of a range of new axially-disubstituted silicon phthalocyanines with 2-[2-(dimethylamino)ethoxy] or 2-[2-(1,4,7,10,13-pentaoxa-16-azacyclooctadecan-16-yl)ethoxy] groups as axial ligands. 2-[2-(Dimethylamino)ethoxy]ethanol 2, 2-[2-(1,4,7,10,13-pentaoxa-16-azacyclooctadecan-16-yl)ethoxy]ethanol 4 are reacted with silicon phthalocyanine 1, to give an axially-disubstituted silicon phthalocyanines 3 and 5. Axially-disubstituted silicon phthalocyanine complexes were synthesized at the first time. Newly synthesized silicon phthalocyanines were characterized by UV-Vis, IR, (1)H NMR, (13)C NMR spectroscopy, ESI mass spectrometry. These new silicon(IV) phthalocyanines 3 and 5 showed excellent solubility in organic solvents such as CHCl(3), CH(2)Cl(2), acetone, DMF, DMSO, THF, EtOAc. The aggregation behavior of these compounds were investigated in different concentrations of DMSO. The effect of solvents on absorption spectra were studied in various organic solvents. The thermal stabilities of the silicon(IV) phthalocyanines 3 and 5 were determined by thermogravimetric analysis.