Zn Pc Research Articles

Catalytic and Selective Red Light-Triggered Photodegradation of a G-Quadruplex DNA by a Zinc (II) Phthalocyanine.

Water-soluble phthalocyanine (Pc) derivatives have been regarded as potential G-quadruplex (G4) nucleic acid-targeting ligands for anticancer therapy and have been extensively studied as effective photosensitizers for photodynamic therapy (PDT). Understanding how photosensitizers interact with nucleic acids and the subsequent photolytic reactions is essential for deciphering the initial steps of PDT, thereby aiding in the development of new photosensitizing agents. In this study, we found that red-light irradiation of a mixture of a Zn(II) Pc derivative and an all-parallel G4 DNA leads to catalytic and selective photodegradation of the DNA by reactive oxygen species (ROS) generated from the Zn(II) Pc derivative bound to DNA through a reaction mechanism similar to that of an enzyme reaction. This finding provides a novel insight into the molecular design of a photosensitizer to enhance its PDT efficacy.

Exploring the Role of Central Metals in Bulky Phthalocyanines for Dye-Sensitized Solar Cells.

Two series of metallo-(Zn(II), Mg(II), and Ru(II)) and free-base phthalocyanines (Pcs) with a carboxyl anchoring group and well-established bulky peripheral substituents (either tert-butyl or bulky 2,6-diisopropylphenoxy) were synthesized and tested as sensitizers in dye-sensitized solar cells (DSSCs). The trend of photovoltaic efficiencies (PCEs) for free-base and metallo Pcs followed the order Zn(II)Pc>Mg(II)Pc≫H2Pc ≈ Ru(II)Pc regardless of the peripheral substitution. Higher efficiencies (4.95 versus 3.63 for the Zn(II) derivatives) were achieved with Pcs bearing the bulkier 2,6-diisopropylphenoxy group, indicating a lower aggregation and more suitable HOMO-LUMO levels. Furthermore, these derivatives showed a morelevant influence of the metal on the PCE values (from the highest 4.95 for the Zn(II)Pc to the lowest 0.23 for the Ru(II)Pc. In both series, the best PCEs observed with the Zn(II) derivatives were mainly due to their highest Jsc values. The lowest efficiencies found for the free-bases and Ru(II) derivatives were attributed to a mismatch between their LUMO levels and the conduction band of the TiO2,and lower light-harvesting capabilities, respectively. In conclusion, Zn(II) derivatives are still the best Pc candidates to use as sensitizers in molecular photovoltaics.

The phenoxy-bearing naphthalimide substituted phthalocyanines: Photophysicochemical and biological properties

A new Si(IV) phthalocyanine (Pc) (1) derivative comprising axially phenoxy-bearing naphthalimide and peripherally t-butyl groups was synthesised and the photophysicochemical properties of this compound were investigated as an antioxidant and antimicrobial agent. Furthermore, the biological properties of the Si(IV) Pc compound (1) and its Zn(II) and Ga(III) Pc derivatives with a peripherally attached phenoxy-bearing naphthalimide group(2 and 3) were assessed in this study. While these compounds exhibited moderate antioxidant effects, their DNA nuclease activities were highly satisfactory. The compounds demonstrated effective antimicrobial activity, particularly following the photodynamic therapy. The most effective minimum inhibitory concentration value was obtained as 4 mg/L against E. faecalis and S. aureus. All compounds inhibited 100 % microbial cell viability at 125 mg/L. The biofilm formation ability of P. aeruginosa and S. aureus was significantly inhibited by all of the Pc compounds. Furthermore, experimental data were supported by TD-DFT calculations and NTO analyses, and the orbital densities of the compounds were shown.

Comparison of the photochemical properties of phthalocyanine and hemiporphyrazine Zn(II) complexes

In DMF (dimethylformamide) solutions containing concentrations of (NEt4)Br (Et = ethyl) between 0.001 and 0.05 M both zinc phthalocyanine (Pc) and hemiporphyrazine (Hp) complexes are dissolved and form species [Zn(Hp)(Br)]–, and [Zn(Pc)(Br)]–. The increase in formation of the hemiporphyrazine bromide adduct is revealed by a linear dependence of the UV–Vis absorption spectrum on the Br– concentration whereas, over the same concentration range, absorption measurements indicate the formation of the phthalocyanine bromide adduct in solution. The x-ray and molecular structure of [NEt4][Zn(Pc)(Br)](H2O)0.33 has been determined showing the coordination of the Br– to the metal center. Photo-induced processes of the Zn complexes were investigated with deaerated solutions in a time scale t ≥10 ns. The 355 nm flash irradiation of [Zn(Hp)(Br)]– produced transient spectra which showed a bathochromic shift of the absorption maximum from 460 nm to 440 nm and an increase of the spectrum rate of decay with increasing Br– concentrations. The initial spectrum is attributed to the (nπ*–LLCTBr→Hp)[Zn(Hp)(Br)]– excited state which reacts with H-atom donors forming a radical [Zn(Hp-H)(Br)]•–. On the other hand, a transient spectrum, λmax ∼600 nm, grows in a time t ≤0.6 µs when [Zn(Pc)(Br)]– is flash irradiated at 355 nm. The photoreactions of these complexes with SCN– and 2-propanol (IPA) were studied. Despite of the apparent similarity between both complexes, IPA was photo-oxidized by both complexes although by different mechanisms, an electron transfer with [Zn(Pc)(Br)]– and an H atom abstraction with [Zn(Hp)(Br)]–. The photo-oxidation of SCN– by [Zn(Pc)(Br)]– but not by [Zn(Hp)(Br)]– makes a remarkable difference between the photochemistries of these complexes.

Enhanced mitochondria destruction on MCF-7 and HeLa cell lines in vitro using triphenyl-phosphonium-labelled phthalocyanines in ultrasound-assisted photodynamic therapy activity.

This work reports on the reactive oxygen species (ROS) generation and the therapeutic activities of new triphenyl-phosphonium-labelled phthalocyanines (Pcs), the 2,9,16,23-tetrakis(N-(N-butyl-4-triphenyl-phosphonium)- pyridine-4-yloxy) Zn(II) Pc (3) and 2,9,16,23-tetrakis-(N-(N-butyl-4-triphenyl-phosphonium)-morpholino) Zn(II) Pc (4) upon exposure to light, ultrasound and the combination of light and ultrasound. Two types of ROS were detected: the singlet oxygen (1O2) and hydroxyl radicals. For light irradiations, only the 1O2 was detected. An increase in the ROS generation was observed for samples treated with the combination of light and ultrasound compared to the light and ultrasound mono-treatments. The in vitro anticancer activity through photodynamic (PDT) and sonodynamic (SDT) therapy for the Pcs were also determined and compared to the photo-sonodynamic combination therapy (PSDT). The two cancer cell lines used for the in vitro studies included the Michigan Cancer Foundation-7 (MCF-7) breast cancer and Henrietta Lacks (HeLa) cervical cancer cell lines. The SDT treatments showed improved therapeutic efficacy on the cancer cells for both the Pcs compared to PDT. PSDT showed better therapeutic efficacy compared to both the PDT and SDT mono-treatments.

The in vitro photo-sonodynamic combinatorial therapy activity of cationic and zwitterionic phthalocyanines on MCF-7 and HeLa cancer cell lines

The syntheses and characterization studies of zwitterionic 2,9,16,23-tetrakis-(N-propane sultone-morpholino) zinc(II) (4) and 2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-propane sultone-morpholinomethyl))-phenoxy zinc(II) (6) phthalocyanines are reported in this work. The photophysical properties, reactive oxygen species (ROS) generation and in vitro anticancer photodynamic (PDT), sonodynamic (SDT), and photo-sonodynamic combination (PSDT) therapy activities of the Pcs were studied and compared to their cationic counterparts: (2,9,16,23-tetrakis-(N-methyl-morpholino) Zn(II)Pc, 3), (2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-methylmorpholine)-phenoxy) Zn(II)Pc, 5). The cationic Pcs maintained higher anticancer activity for all treatment types and had higher ROS generation compared to the zwitterionic Pcs. Singlet oxygen and hydroxyl radicals were generated during ultrasound and combination irradiations of the Pcs. The zwitterionic Pcs also generated carbon radicals under ultrasound and combination irradiations. The ability of the Pcs to generate ROS is essential for PDT, SDT and PSDT, thus making these Pcs potential anticancer probes for these treatment types. Furthermore, the Pcs demonstrated the ability to bind to bovine serum albumin protein.

Preparation of Zinc (II) phthalocyanine-based LB thin film: Experimental characterization, the determination of some optical properties and the investigation of the optical sensing ability

Zinc(II) phthalocyanine (Zn(II)Pc) molecule was the first time prepared onto three different substrates utilizing Langmuir-Blodgett (LB) deposition technique to investigate its vapor sensing abilities and some optical properties. We utilized five different and well-known techniques to control monolayer quality of Zn(II)Pc LB film. The obtained the thickness and refractive index values for Zn(II)Pc LB film with coated at different layers vary from 3.2 to 10.9 nm and from 1.42 to 1.71, respectively. The sensing properties were investigated by exposing the Zn(II)Pc-based mass or optical sensor to some organic vapors. Kinetic results presented that this Zn(II)Pc material is a good candidate as a sensor element with a fast and reversible response for dichloromethane sensing devices.

Photochemical properties of fluoro-chalcone substituted peripherally tetra Zn(II)Pc and Mg(II)Pc

Fluoro-chalcone substituted new metallophthalocyanines (MPcs) (M = Zn or Mg) derived from (2E)-1-(3-hydroxyphenyl)-3-(2,4,5-trifluorophenyl)prop-2-en-1-one were synthesized. The structures of chalcone compound 1, phthalonitrile derivative 2 and metallophthalocyanines 3, 4 were characterized by a combination of spectroscopic techniques such as “FT-IR, 1H NMR, 13C NMR, MALDI–TOF mass and UV–Vis” as well by elemental analysis. The aggregation behaviours and photochemical properties such as singlet oxygen and photodegradation quantum yields of the synthesized ZnIIPc 3 and MgIIPc 4 were examined in DMSO.

Antifungal photodynamic activities of phthalocyanine derivatives on Candida albicans.

Antimicrobial resistance is one of the most important causes of morbidity and mortality in the treatment of infectious diseases worldwide. Candida albicans is one of the most virulent and common species of fungi to cause invasive fungal infections on humans. Alternative treatment strategies, including photodynamic therapy, are needed for controlling these infectious diseases. The aim of this study was to investigate the antifungal photodynamic activities of phthalocyanine derivatives on C. albicans. The minimum inhibitory concentration (MIC) values of compounds were determined by the broth microdilution method. Uptake of the compounds in C. albicans and dark toxicity of the compounds were also investigated. Photodynamic inhibition of growth experiments was performed by measuring the colony-forming unit/mL (CFU/mL) of the strain. Maximum uptake into the cells was observed in the presence of 64 μg/mL concentration for each compound except for ZnPc. Compounds did not show dark toxicity/inhibitory effects at sub-MIC concentrations on C. albicans when compared to the negative control groups. Zn(II)Pc, ZnPc, and ZnPc-TiO2 showed fungicidal effect after irradiation with the light dose of 90 J/cm2 in the presence of the compounds. In addition to the fungicidal effects, SubPc, SubPc-TiO2, Es-SiPc, and Es-SubPc compounds were also found to have inhibitory effects on the growth of yeast cells after irradiation.

Assessing Amphiphilic ABAB Zn(II) Phthalocyanines with Enhanced Photosensitization Abilities in In Vitro Photodynamic Therapy Studies Against Cancer.

We have previously demonstrated that singlet oxygen photosensitization abilities of Zn(II) phthalocyanines (Zn(II)Pcs) are enhanced through α-functionalization with bulky fluorinated substituents (i.e., bis(trifluoromethyl)phenyl units) at facing positions of ABAB Zn(II)Pcs, where A and B refer to differently functionalized isoindoles. In this work, we have prepared the Zn(II)Pc ABAB 1 endowed with hydrophilic triethylene glycol monomethyl ether (i.e., at the A isoindoles) to provide solubility in aqueous media, together with its A3B and A4 counterparts, and compared their ability to behave as photosensitizers for photodynamic therapy. All photophysical data, aggregation studies and preliminary in vitro biological assays in cell cultures of SCC-13 (squamous cell carcinoma) and HeLa (cervical cancer cells), have proved ABAB 1 as the best photosensitizer of the series.

Phthalocyanine-corannulene conjugates: Synthesis, complexation studies with a pyridyl-functionalized C60 fullerene, and photophysical properties

We report here the synthesis and characterization of some novel Zn(II)phthalocyanine (Pc)-corannulene conjugates and their complexation ability towards a pyridyl-functionalized C[Formula: see text] fullerene through metal-ligand supramolecular interactions. Steady-state and time-resolved photophysical studies carried out on these electron donor–acceptor (D–A) Zn(II)Pc-corannulene/C[Formula: see text] ensembles indicate the formation of photogenerated charge-separated species. Interestingly, a stabilization of the photoinduced charge-separated state is observed in the case of the D–A supramolecular complexes comprising the corannulene-substituted Zn(II)Pcs when compared to their non-corannulene functionalized Zn(II)Pc analogues. We rationalize this stabilizing effect of the charge-separated state exerted by the corannulene as a result of the increased [Formula: see text]-extension and augmented hydrophobicity of the Zn(II)Pc core by the covalently-linked polyaromatic hydrocarbon (PAH) fragment.

Phthalocyanine and Metal Phthalocyanines Adsorbed on Graphene: A Density Functional Study

Geometries of phthalocyanine (Pc) and metal (M = Cu, Fe, Zn, and Sn) Pc (MPc) adsorption on graphene have been studied using van der Waals density functional theory, which takes into account nonloc...

Construction of a supramolecule comprising [2,3,9,10,16,17,23,24-octakis(2,6-dimethylphenoxy)phthalocyaninato]zinc(II) and (5,10,15,20-tetraphenylporphyrinato)zinc(II)

The supramolecular features in the title compound, [2,3,9,10,16,17,23,24-octakis(2,6-dimethylphenoxy)phthalocyaninato]zinc(II) bis[(5,10,15,20-tetraphenylporphyrinato)zinc(II)] chloroform tetrasolvate, [Zn(C96H80N8O8)][Zn(C44H28N4)]2·4CHCl3 or [Zn(Pc)][Zn(TPP)]2·4CHCl3, result from a self-assembly of one molecule of [2,3,9,10,16,17,23,24-octakis(2,6-dimethylphenoxy)phthalocyaninato]zinc(II) (ZnPc) and two molecules of (5,10,15,20-tetraphenylporphyrinato)zinc(II) (ZnTPP). One half ZnPc, one ZnTPP and two chloroform molecules define the asymmetric unit, with the zinc(II) cation of ZnPc situated on an inversion centre. In the supramolecule, the central ZnPc moiety is sandwiched between two ZnTPPs moieties in a co-facial conformation with a π-conjugated system, leading to a nearly H-type aggregate with a distance of 3.4967 (5) Å between adjacent zinc sites. The ZnTPP units are slightly glided away to form a partial ecliptic arrangement. Each phenyl group of the TPP ligand is anchored above the N atom of the isoindole linker of the Pc ligand through weak C—H...N hydrogen bonds and is held into the crevice between the two dimethylphenoxy groups of phthalocyanine via van der Waals interactions. In the crystal, chloroform solvent molecules are situated between the supramolecules. There is another solvent-accessible void of 341 (2) Å3. The contribution of disordered solvent molecules situated in this void was removed from the diffraction data using SQUEEZE in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The given chemical formula and other crystal data do not consider this unknown solvent molecule(s).

Synthesis, characterization, and electrochemical and in-situ spectroelectrochemical properties of novel peripherally and non-peripherally 7-oxy-3-(3,4-dimethoxyphenyl) coumarin substituted phthalocyanines

Novel metal-free (4 and 9), Zn(II) (5 and 10) and Co(II) (6 and 11) phthalocyanines (Pcs) bearing four 7-oxy-3-(3,4-dimethoxyphenyl)coumarin (1) substituents at peripheral (β) and non-peripheral (α) positions have been prepared by cyclotetramerization reactions of 4-(3-(3,4-dimethoxyphenyl)coumarin-7-oxy)phthalonitrile (3) or 3-(3-(3,4-dimethoxy-phenyl)coumarin-7-oxy)phthalonitrile (8), respectively, in the presence of relevant metal acetate salts in N,N-dimethylaminoethanol. The compounds have been characterized by elemental analysis, FT-IR, UV–Vis and MALDI-TOF mass spectroscopies. Thermal properties of the compounds were evaluated by thermogravimetric analysis and differential scanning calorimetry. Electrochemical redox properties of all compounds were investigated by voltammetric and in-situ spectroelectrochemical measurements in dimethylsulfoxide including tetrabutyl ammonium perchlorate as the supporting electrolyte. The metal-free and Zn(II)Pc compounds displayed Pc ring-based redox processes whereas both Pc ring-based and metal-based electron transfer processes were observed for Co(II)Pc complexes. H-aggregation tendency of peripherally substituted compounds was found to be much higher than that of non-peripherally substituted ones. It was observed that there have been systemmatic redox potential and aggregation behaviour differences between the peripherally and non-peripherally substituted Pc compounds. These differences were attributed to different sterical and conformational effects of these substitution patterns. In-situ spectroelectrochemical and in-situ electrocolorimetric measurements suggested that peripherally substituted Co(II)Pc is a multi-coloured chromophore material displaying distinct spectral and colour changes during the first reduction and oxidation processes, and thus, being suitable for electrochromic applications.

Catalytic selectivity of metallophthalocyanines for electrochemical nitric oxide sensing

The catalytic properties of metallophthalocyanine (MPc) complexes have long been applied to electrochemical sensing of nitric oxide (NO) to amplify sensitivity and reduce the substantial overpotential required for NO oxidation. The latter point has significant ramifications for in situ amperometric detection, as large working potentials oxidize biological interferents (e.g., nitrite, l-ascorbate, and carbon monoxide). Herein, we sought to isolate and quantify, for the first time, the selectivity benefits of MPc modification of glassy carbon electrodes. A series of the most catalytically active MPc complexes towards NO, including Fe(II)Pc, Co(II)Pc, Ni(II)Pc, and Zn(II)Pc, was selected and probed for NO sensing ability under both differential pulse voltammetry (DPV) and constant potential amperometry (CPA). Data from DPV measurements provided information with respect to MPc signal sensitivity amplification (∼1.5×) and peak shifting (100–200 mV). Iron-Pc exerted the most specific catalytic activity towards NO over nitrite. Catalyst-enabled reduction of the working potential under CPA was found to improve selectivity for NO over high potential interferents, regardless of MPc. However, impaired selectivity against low potential interferents was also noted.

Breaching the wall: morphological control of efficacy of phthalocyanine-based photoantimicrobials.

An efficient treatment of infections using antimicrobial photodynamic therapy (aPDT) anticipates that uptake of photosensitizer (PS) by bacterial cells is very fast and effective. In this work, the design, synthesis, characterization, and photodynamic activity of amphiphilic, water-soluble zinc(ii)phthalocyanine (Zn(ii)Pc) molecules bearing none, three or six thiophenyl moieties are described. We show that PSs that contain no or flexible substituents on non-peripheral positions can photoinactivate microbes at very low loading concentrations and low light doses. In contrast, a PS derivative that contains non-flexible substituents is rendered less effective, despite an increased generation of cytotoxic singlet oxygen, higher lipophilicity and a lower tendency to aggregate. Our unexpected finding emphasizes the role of the morphology of PSs in bacterial cell-molecule interactions and suggests another relevant and hitherto disregarded characteristic to improve PS design.

Study of all-optical switching properties of zinc phthalocyanine thin film by pump-probe technique

The nonlinear optical absorption, refraction and switching behavior of Zinc phthalocyanine (Zn(II)Pc) thin films are reported. Z-scan technique is employed to study the nonlinear absorption and nonlinear refraction behavior of the thin films with nanosecond pulses of Nd:YAG laser at ∼532nm. Optical switching behavior of the dye is studied using pump-probe technique with ∼5ns pulses of Nd:YAG at ∼532nm as the pump beam and ∼632.8nm cw He-Ne laser as the probe beam. The switching behavior of the dye is attributed to excited state absorption (ESA) of the probe beam by the dye molecules. Probe beam modulation with increasing pump intensity is also investigated.

Dual Nuclear/Fluorescence Imaging Potantial of Zinc(II) Phthalocyanine in MIA PaCa-2 Cell Line.

Pancreatic cancer is very common and difficult to diagnose in early stage. Imaging systems for diagnosing cancer have many disadvantages. However, combining different imaging modalities offers synergistic advantages. Optical imaging is the most multidirectional and widely used imaging modality in both clinical practice and research. In present study, Zinc(II) phthalocyanine [Zn(II)Pc] was synthesized, labeled with iodine- 131 and in vitro study was carried out. The intracellular uptake studies of radiolabeled Zn(II)Pc were performed in WI-38 [ATCC CCL-75™, tissue: human fibroblast lung] and MIA PaCa-2 [ATCC CRL-1420™, tissue: human epithelial pancreas carcinoma] cell lines. The intracellular uptake efficiency of radiolabeled Zn(II)Pc in MIA PaCa-2 cells was determined two times higher than WI-38 cells. Also, fluorescence imaging (FI) efficiency of synthesized Zn(II)Pc was investigated in MIA PaCa-2 cells and significant uptake was observed. Zn(II)Pc might be used as a new agent for dual fluorescence/nuclear imaging for pancreatic cancer.

Evaluation of nuclear imaging potential and photodynamic therapy efficacy of symmetrical and asymmetrical zinc phthalocyanines

Photodynamic therapy (PDT) is a medical treatment for the removal of target tissues involving the delivery of a photosensitizer agent followed by irradiation with visible light. In the present study, symmetric Zn(II)Pc 1 and asymmetrically substituted Zn(II)Pc 2 were synthesized and examined multifunctional agents for tumor nuclear imaging and PDT potential. The Zn(II)Pc 1 and Zn(II)Pc 2 were radiolabeled with 131I with high efficiency (93.4 ± 1.6% and 91.4 ± 1.6%, respectively). The results of the biodistribution study showed that radiolabeled Zn(II)Pc 1 had high uptake on lung, large intestine, ovary and pancreas. However, the uptake of radiolabeled Zn(II)Pc 2 was statically significant in pancreas and intestine. In PDT studies, EMT6/P (mouse mammary cell) and HeLa (cervical adenocarcinoma cell) with Zn(II)Pc 1 and Zn(II)Pc 2 were exposed to red light at the doses of 10–30 J/cm2. Although PDT activity of Zn(II)Pc 2 in HeLa cell line was determined, Zn(II)Pc 1 showed no phototoxic effect in both cell lines. In conclusion, radiolabeled Zn(II)Pc 1 might be a promising imaging agent for the lung, the ovary pancreas, and the colon tumors. However, radiolabeled Zn(II)Pc 2 might be a promising nuclear imaging agent for the colon and the pancreas tumors and promising PDT agent for cervical tumors.

Nuclear imaging potential and in vitro photodynamic activity of symmetrical and asymmetrical zinc phthalocyanines.

Photodynamic therapy (PDT) is based on exposing a light-sensitive material that has been localized in target tissues with visible light. In the current study, symmetric Zn(II) octaoctadodecylphthalocyanine (1) and the asymmetrically substituted hydroxyhexyloxy derivative (2) were examined as a multifunctional agent for tumour nuclear imaging and for PDT potential. Zn(II)Pc 1 and Zn(II)Pc 2 were radiolabelled with (131) I using an iodogen method with high efficiency (93.5 ± 3.5% and 93.0 ± 2.8%, respectively) under the optimum conditions. Biodistribution study results showed that radiolabelled Zn(II)Pc 1 had a high uptake in the large intestine and unchanging uptake in the ovary. However, radiolabelled Zn(II)Pc 2 uptake was statically significant in the large intestine, pancreas, ovary and lung. For the PDT studies, EMT6/P (mouse mammary cell line) and HeLa (cervical adenocarcinoma cell line) with Zn(II)Pc 1 and Zn(II)Pc 2 were exposed to red light (650 nm) at 10-30 J/cm(2) . Zn(II)Pc 1 and Zn(II)Pc 2 had a good PDT efficacy in the EMT6/P cell line. In conclusion, radiolabelled Zn(II)Pc 1 might be a promising imaging agent for pancreas, ovary and colon tumours. However, the radiolabelled Zn(II)Pc 2 might be a promising nuclear imaging and PDT agent for colon, lung, pancreas and ovary tumours.