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Phthalocyanines are tetrapyrrolic artificial porphyrinoids that play major roles in advanced biological and technological applications. Research on this family of dyes is particularly active in Türkiye, with many derivatives being prepared from 4,5-dihexylthiophthalonitrile DiSHexPN, which is one of the most popular noncommercially available building blocks for phthalocyanines. This review summarizes the phthalocyanines and their versatile properties and applications that have been published since 1994, when the synthesis of DiSHexPN was first described, to emphasize the importance of this building block in plentiful applications, all with biomedical or technological impact. [ABSTRACT FROM AUTHOR]

Phthalocyanines exhibit superior photoproperties that make them a surely attractive class of photosensitisers for photodynamic therapy of cancer. Several derivatives are at various phases of clinical trials, and efforts have been put continuously to improve their photodynamic efficacy. To this end, various strategies have been applied to develop advanced phthalocyanines with optimised photoproperties, dual therapeutic actions, tumour-targeting properties and/or specific activation at tumour sites. The advantageous properties and potential of phthalocyanines as advanced photosensitisers for photodynamic therapy of cancer are highlighted in this tutorial review. [ABSTRACT FROM AUTHOR]

A new efficient synthetic route was used to obtain symmetrically and asymmetrically substituted gallium(iii) phthalocyanines (5-GaCl and 6-GaCl) containing azido groups with chlorine atoms at axial positions, using corresponding ZnPc derivatives (5-Zn and 6-Zn) as precursors. The photophysical and photochemical properties―fluorescence, singlet oxygen generation, and photodegradation―of 5-GaCl and 6-GaCl were compared with that of 5-Zn and 6-Zn. Their pH-sensitive spectral changes were also investigated in detail, as tumours are more acidic than healthy tissues. Their amphiphilicity, quantified by their partition coefficient, appeared suitable for biological applications. 5-GaCl and 6-GaCl exhibited higher photodynamic potential than unsubstituted gallium(iii) phthalocyanine, suggesting potential to be used as a photodynamic therapy agent. [ABSTRACT FROM AUTHOR]

Phthalonitriles are key precursors of phthalocyanines. Self-quenching dimeric phthalocyanines likely to be cleaved into monomeric species are of potential interest for tumour-site activated photosensitisers. Disulfide linkers can be specifically cleaved in tumoral tissue do to their reductive nature. Hence, a disulfide-linked phthalonitrile was designed to serve as further precursor of specifically tumour-activatable phthalocyanine-based photosensitising systems. Bisphthalonitrile with a disulfide-based linker and its dimethylene analogue were comparatively analyzed on a spectroscopic point of view as well as with DFT calculations. A thorough crystallographic analysis of the disulfide-linked derivative was conducted. [ABSTRACT FROM AUTHOR]

4-tert-Butylbenzenesulfonamide was used as a substituent of tetra peripherally substituted Fe(II) phthalocyanine, taking into account several parameters crucial for the design of potential oxidation catalysts such as solubility and stability. The resulting phthalocyanine exhibits a remarkable stability under oxidative conditions. The main product of the oxidation of cyclohexene using H2O2 as the oxidant is the allylic ketone, 2-cyclohexen-1-one. Styrene oxidation led mainly to the formation of benzaldehyde. [ABSTRACT FROM AUTHOR]

The design and synthesis of a phthalocyanine - Gd- DOTA conjugate is presented to open the way to novel molecular theranostics, combining the properties of MRI contrast imaging with photodynamic therapy. The rational design of the conjugate integrates isomeric purity of the phthalocyanine core substitution, suitable biocompatibility with the use of polyoxo water-solubilizing substituents, and a convergent synthetic strategy ended by the use of click chemistry to graft the Gd- DOTA moiety to the phthalocyanine. Photophysical and photochemical properties, contrast imaging experiments and preliminary in vitro investigations proved that such a combination is relevant and lead to a new type of potential theranostic agent. [ABSTRACT FROM AUTHOR]

Among possible asymmetrically substituted phthalocyanines, ABAB derivatives remain rare. Their selective synthesis is based on the use of trichloroisoindolenines, so far remaining tedious to obtain. An optimized synthesis of 1,3,3-trichloroisoindolenine 1 and 1,3,3,6,7-pentachloroisoindolenine 2 is reported. An original crystallization method based on crystal growth by sublimation was eminently suitable regarding the air-sensitivity of these derivatives and allowed their thorough crystallographic characterization. [ABSTRACT FROM AUTHOR]

A phthalocyanine-fluorescein conjugate was designed and prepared. Its photophysical properties (electronic absorption and fluorescence) were determined and compared with those of an analogous derivative functionalized by a simple triazole without chromophore. It is likely to be used as a theranostic agent in photodynamic therapy. [ABSTRACT FROM AUTHOR]

Three Zn(ii) phthalocyanines substituted by hydroxyl-terminated tetraethylene glycol chains have been synthesized. In order to evaluate the potential of these highly water-soluble phthalocyanines as type II-photosensitisers for photodynamic therapy, their structure–activity relationship was assessed by determining relevant photophysical and photochemical properties, such as their aggregation behaviour in aqueous buffers, their fluorescence properties and their efficiency with regard to the generation of singlet oxygen. In addition, evidence for a negligible interaction with plasma proteins in undiluted human plasma was obtained using a recently developed bioanalytical method and compared with the fluorescence quenching approach. These results combined with in vitrodata regarding the phototoxicity of these phthalocyanines against HT-29 cancer cells provide evidence for the relevance of the non-peripherally substituted derivative for further in vivoinvestigations. [ABSTRACT FROM AUTHOR]

Abstract: A series of asymmetrically substituted phthalocyanines conjugated to four different carbohydrate units has been designed to be used as photosensitisers for potential selective recognition by targeted cells. [Copyright &y& Elsevier]

Abstract: The different types of water-soluble phthalocyanines are presented and their synthesis is reviewed. [ABSTRACT FROM AUTHOR]

Two series of amphiphilic carbohydrate–phthalocyanine conjugates have been prepared either by glycosylation or by copper-catalyzed click coupling. A common precursor, a hydroxylated phthalocyanine, was directly glycosylated or converted into an azido derivative before undergoing grafting of propargyl–carbohydrates by click reaction. [ABSTRACT FROM AUTHOR]

Abstract: A complete set of platinum(II) solketal substituted phthalocyanines has been synthesized and characterized. To evaluate their potential as Type II photosensitizers for photodynamic therapy, comparative studies of their photophysical and photochemical properties with analogous zinc(II) series have been achieved: electronic absorption, fluorescence quantum yields, lifetimes, and fluorescence quenching by benzoquinone, as well as singlet oxygen generation and photodegradation. It appears that platinum(II) phthalocyanines are worth being used as Type II photosensitizers, as they exhibit good singlet oxygen generation and appropriate photodegradation. [Copyright &y& Elsevier]

A one-step method to access to functionalized heteroleptic lanthanide double-decker complexes of phthalocyanine of A7B-type is reported. This optimized statistical method led to two hydroxylated model europium complexes, one of which was further converted into its mesylated and azido derivatives. [ABSTRACT FROM AUTHOR]

Abstract: Palladium-catalyzed copper-free Sonogashira cross-coupling reactions were performed on a protected and unprotected monoiodotriglycerol substituted Zn(II) phthalocyanine with various alkynes in organic and aqueous medium. From the silyl protected alkyne derivative, a protected homo coupled dimeric product was also prepared using Glaser coupling. All products were purified by reverse phase HPLC and the assigned structures were confirmed by mass and UV–vis spectroscopy. [Copyright &y& Elsevier]

Molecular catalysts that combine high product selectivity and high current density for CO2 electrochemical reduction to CO or other chemical feedstocks are urgently needed. While earth-abundant metal-based molecular electrocatalysts with high selectivity for CO2 to CO conversion are known, they are characterized by current densities that are significantly lower than those obtained with solid-state metal materials. Here, we report that a cobalt phthalocyanine bearing a trimethyl ammonium group appended to the phthalocyanine macrocycle is capable of reducing CO2 to CO in water with high activity over a broad pH range from 4 to 14. In a flow cell configuration operating in basic conditions, CO production occurs with excellent selectivity (ca. 95%), and good stability with a maximum partial current density of 165 mA cm−2 (at −0.92 V vs. RHE), matching the most active noble metal-based nanocatalysts. These results represent state-of-the-art performance for electrolytic carbon dioxide reduction by a molecular catalyst. Molecular electrocatalysts reducing CO2 to CO with high selectivity and high rate are urgently needed. A cobalt phthalocyanine complex is capable of reducing CO2 to CO in water with a maximum partial current density up to 165 mA cm−2, matching the most active noble metal-based nanocatalysts. [ABSTRACT FROM AUTHOR]

• µ-nitrido diiron phthalocyanine and porphyrin complexes were prepared. • The catalytic activities of µ-nitrido diiron phthalocyanine and porphyrin complexes were tested in oxidation of several alcohols. • Mechanistic and computational studies were made. µ-Nitrido diiron porphyrinoids complexes, based either on porphyrins or phthalocyanines, are known as excellent oxidation catalysts. While many works have investigated the effect of the substitution pattern on their catalytic activity, a comparison of the effect of the macrocycle remains yet to be conducted. For this purpose, tert -butyl substituted (FePc) 2 N and (FePor) 2 N have been selected as they have both been thoroughly but separately used for oxidation catalysis. Herein, their catalytic activities were tested on model oxidation reactions of various alcohols. The phthalocyanine-based complex (FePc) 2 N proved to be a far more efficient catalyst than its porphyrin counterpart (FePor) 2 N. Computational studies rationalized these experimental observations by showing that the intermediates formed by (FePc) 2 N are thermodynamically more stable than those formed by (FePor) 2 N. [Display omitted] [ABSTRACT FROM AUTHOR]

• Organic heterojunction devices based on phthalocyanine complexes are fabricated. • Electronic effects of substituents in phthalocyanine influence interfacial conductivity. • Heterojunction devices displayed positive and negative response towards NH 3. • Ambipolar sensing behavior towards NH 3 is revealed for one of the sensors. Exploiting organic heterojunction effects in electrical devices are an important strategy to improve the electrical conductivity, which can be utilized into improving the conductometric gas sensors performances. In this endeavor, the present article reports fabrication of organic heterostructures in a bilayer device configuration incorporating octa-substituted nickel phthalocyanines (NiPc) and radical lutetium bis-phthalocyanine (LuPc 2) and investigates their sensing properties towards NH 3 vapor. NiPc having hexyl sulfanyl, hexyl sulfonyl and p -carboxyphenoxy moieties are synthesized, which electronic effects are electron donating, accepting and moderate accepting, respectively, also validated by cyclic voltammetry. The electronic effects of substituents in NiPc modulate the interfacial electrical conductivity and the type of the organic heterojunction formed. The electron acceptor and donor groups favor the formation of accumulation and accumulation/depletion heterojunctions, which are also correlated to negative and positive response towards NH 3, respectively. Among the studied heterojunction devices, the one based on hexyl sulfanyl groups, revealed the highest and the most stable response in 10−90 ppm of NH 3 and under variable relative humidity (rh) (10–70 %). Interestingly, the bilayer device having p -carboxyphenoxy substituted NiPc, exhibited ambipolar behavior such that its p-type semiconducting nature is changed into n-type at higher rh values, also demonstrated by change in its negative response into positive towards NH 3. [ABSTRACT FROM AUTHOR]

A fluorinated phthalocyanine and its non-fluorinated analogue were selected to evaluate the potential enhancement of fluorination on photophysical, photochemical and redox properties as well as on biological activity in cellular and animal models. Due to the pharmacological relevance, the affinity of these phthalocyanines towards biological membranes (logP ow ) as well as their primary interaction with human serum albumin (HSA) or low-density lipoprotein (LDL) were determined. Water-dispersible drug formulation of phthalocyanines via Pluronic ® -based triblock copolymer micelles was prepared to avoid self-aggregation effects and to improve their delivery. The obtained results demonstrate that phthalocyanines incorporation into tunable-polymeric micelles significantly enhanced their cellular uptake and their photocytotoxicity. The improved biodistribution and photodynamic efficacy of the phthalocyanines-triblock copolymer conjugates was also confirmed in vivo in CT26 bearing BALB/c mice. PDT with both compounds led to tumor growth inhibition in all treated animals. Fluorinated phthalocyanine 2 turned out to be the most effective anticancer agent as the tumors of 20% of mice treated regressed completely and did not appear for over one year after treatment. [ABSTRACT FROM AUTHOR]

Review: 283 refs. [ABSTRACT FROM AUTHOR]