Synthesis and studies on photodynamic activity of new water-soluble azaphthalocyanines

Spectroscopic characterization and aggregation of azine compounds in different media

“…It can be concluded that the introduction of a bulky substituent not only enhanced the lipophilic character of NR, but also prevented its molecular aggregation in solution due to a steric reason, potentially resulting in superior photochemical and photophysical characteristics, which enhanced the PDT properties [39,40]. Nevertheless, these observations contradict the predictions of some authors who argue that increasing the lipophilicity of compounds, causes a rise in their aggregation tendencies [12,41].…”

Synthesis and properties of azaphthalocyanines with 1,2,3,4-tetrahydropyrazino[2,3-b]pyrazine moiety

“…This synthetic pathway was very surprising because nucleophilic substitutions of 5,6-dichloropyrazine-2,3-dicarbonitrile with secondary amines are known to proceed well with high yields and a limited number of the side products. [15,21,22] A plausible mechanism of a tetrahydropyrazine ring formation in this reaction involves nucleophilic substitution of one chlorine atom in 5,6-dichloropyrazine-2,3-dicarbonitrile by secondary amine in the first step. Subsequently, a lone pair of the tertiary amine of the attached substituent attacks the second electrondeficient carbon in the pyrazine ring followed by elimination (most likely ethylene) giving rise to compound 1.…”

Synthesis and spectral properties of tetrapyrazinoporphyrazinato metal complexes derived from sterically hindered phenol

“…4 Analogues of phthalocyanine in which nitrogen replaces some of the carbons within the four fused benzo-substituents of the phthalocyanine, possess significantly different physical properties including color, oxidation potential and stability, which may be beneficial for some of these applications. 5,6 Hence, 1,4,8,11,15,18,22,, often termed tetrapyrazinoporphyrazine in the literature, and its substituted derivatives have been investigated extensively for applications as photodynamic therapeutics, [7][8][9] colorants, 10 catalysts, 11 liquid crystals, [12][13][14] non-linear optical materials 15 and as a red fluorophore. 10,16,17 This latter application is of particular interest as the major phthalocyanine fluorescence band falls in the Near-IR region and is largely invisible to the human eye whereas AzaPc has a very strong fluorescence band in the visible spectrum.…”

“…Due to their extended planar π-conjugated systems, AzaPcs exhibit a high tendency for aggregation which decreases solubility and hinders purification and characterization. Therefore, such unfavorable properties of these macrocyclic compounds greatly reduces their efficiency in PDT 18 and other applications. 19,20 Controlling the morphology of the azaphthalocyanine-based materials affects their performance in the above mentioned applications.…”