Zinc Phthalocyanine Research Articles

A Sulfur-Bridging Sulfonate-Modified Zinc(II) Phthalocyanine Nanoliposome Possessing Hybrid Type I and Type II Photoreactions with Efficient Photodynamic Anticancer Effects

Phthalocyanines are potentially promising photosensitizers (PSs) for photodynamic therapy (PDT), but the inherent defects such as aggregation-caused quenching effects and non-specific toxicity severely hinder their further application in PDT. Herein, we synthesized two zinc(II) phthalocyanines (PcSA and PcOA) monosubstituted with a sulphonate group in the alpha position with "O bridge" and "S bridge" as bonds and prepared a liposomal nanophotosensitizer (PcSA@Lip) by thin-film hydration method to regulate the aggregation of PcSA in the aqueous solution and enhance its tumor targeting ability. PcSA@Lip exhibited highly efficient production of superoxide radical (O2∙-) and singlet oxygen (1O2) in water under light irradiation, which were 2.6-fold and 15.4-fold higher than those of free PcSA, respectively. Furthermore, PcSA@Lip was able to accumulate selectively in tumors after intravenous injection with the fluorescence intensity ratio of tumors to livers was 4.1:1. The significant tumor inhibition effects resulted in a 98% tumor inhibition rate after PcSA@Lip was injected intravenously at an ultra-low PcSA@Lip dose (0.8 nmol g-1 PcSA) and light dose (30 J cm-2). Therefore, the liposomal PcSA@Lip is a prospective nanophotosensitizer possessing hybrid type I and type II photoreactions with efficient photodynamic anticancer effects.

Cobalamin (Vitamin B12) in Anticancer Photodynamic Therapy with Zn(II) Phthalocyanines.

Photodynamic therapy (PDT) is a curative method, firstly developed for cancer therapy with fast response after treatment and minimum side effects. Two zinc(II) phthalocyanines (3ZnPc and 4ZnPc) and a hydroxycobalamin (Cbl) were investigated on two breast cancer cell lines (MDA-MB-231 and MCF-7) in comparison to normal cell lines (MCF-10 and BALB 3T3). The novelty of this study is a complex of non-peripherally methylpyridiloxy substituted Zn(II) phthalocyanine (3ZnPc) and the evaluation of the effects on different cell lines due to the addition of second porphyrinoid such as Cbl. The results showed the complete photocytotoxicity of both ZnPc-complexes at lower concentrations (<0.1 μM) for 3ZnPc. The addition of Cbl caused a higher phototoxicity of 3ZnPc at one order lower concentrations (<0.01 μM) with a diminishment of the dark toxicity. Moreover, it was determined that an increase of the selectivity index of 3ZnPc, from 0.66 (MCF-7) and 0.89 (MDA-MB-231) to 1.56 and 2.31, occurred by the addition of Cbl upon exposure with a LED 660 nm (50 J/cm2). The study suggested that the addition of Cbl can minimize the dark toxicity and improve the efficiency of the phthalocyanines for anticancer PDT applications.

Sensor application and mathematical modeling of new Zn(II) phthalocyanine containing 26-membered tetraoxadithia macrocycle moieties

A novel phthalonitrile containing 26-member tetraoxadithia macrocycle moiety was synthesized in a multistep reaction sequence. New zinc(II) phthalocyanine was obtained by the cyclomerization reaction of this macrocyclic phthalonitrile. The novel phthalocyanine and the precursor compounds have been characterized by a combination of 1H and 13C NMR, FT-IR, UV–vis, elemental analysis and MALDI-TOF mass spectral data. 26-membered phthalocyanine was used to fabricate multilayered Langmuir-Blodgett (LB) thin films dedicated to investigating the gas sensing properties of these novel phthalocyanine materials. SEM images of the uncoated substrate, 8-layered and 16-layered LB thin films were compared to observe the successfully transferred layer by layer onto the solid substrates. Sensor parameters such as selectivity, reproducibility, thickness effect, recovery and response rates were examined for highly toxic benzene and toluene vapors using the mass sensitive Quartz Crystal Microbalance (QCM) technique. The first time the thickness effect on the gas sensing mechanism for selected material was also investigated. Validation of the experimental measurements of QCM kinetic was implemented using nonlinear autoregressive with exogenous input neural network for modelling using the frequency shift value. Comparison of these frequency shift of artificial neural network with real-experimental data showed the accuracy of the artificial neural network model.

DNA groove binder and significant cytotoxic activity on human colon cancer cells: Potential of a dimeric zinc (II) phthalocyanine derivative

The interaction of a multi-component system consisting of benzene-1,4-diyldimethanimine-bridged dimeric zinc-phthalocyanine groups (4OMPCZ) with calf thymus DNA (ct-DNA) was investigated using UV–Vis absorption, fluorescence emission spectroscopy methods, and viscosity measurements. The binding constant, Kb, which is an important parameter to gain information about the binding mode, was found as 9.7 × 107 M−1 from the UV–Vis absorption studies. Another important spectrophotometric tool is competitive displacement assays with Ethidium bromide and Hoechst 33342. Through this experiment, a higher KSV value was obtained with Hoechst for the phthalocyanine derivative, 4OMPCZ, and the ct-DNA complex than with ethidium bromide. Additionally, molecular docking studies were conducted to calculate the theoretical binding constant and visualize the interactions of 4OMPCZ with a model DNA. According to docking results, although the interactions are mainly located in the major groove of the DNA helix, due to the wrapping, these interactions can also be extended to the minor groove of the DNA. Spectrophotometric, molecular docking, and viscosity studies revealed that the interaction of 4OMPCZ with DNA is likely to be via the major and minor grooves. The in vitro cytotoxic activity of 4OMPCZ was evaluated by MTT assay on human colon cancer cells (HT29) after 72 h of treatment. 4OMPCZ indicated significant cytotoxic activity when stimulated with UV light compared to the standard chemotherapy drugs, fluorouracil (5-FU), and cisplatin on HT29 colon cancer cells. The IC50 value of 4OMPCZ displayed considerably lower concentrations compared to the standard drugs, 5-FU, and cisplatin.

In Vitro Photoinactivation of Fusarium oxysporum Conidia with Light-Activated Ammonium Phthalocyanines.

Antimicrobial photodynamic therapy (aPDT) has been explored as an innovative therapeutic approach because it can be used to inactivate a variety of microbial forms (vegetative forms and spores) without causing significant damage to host tissues, and without the development of resistance to the photosensitization process. This study assesses the photodynamic antifungal/sporicidal activity of tetra- and octasubstituted phthalocyanine (Pc) dyes with ammonium groups. Tetra- and octasubstituted zinc(II) phthalocyanines (1 and 2) were prepared and tested as photosensitizers (PSs) on Fusarium oxysporum conidia. Photoinactivation (PDI) tests were conducted with photosensitizer (PS) concentrations of 20, 40, and 60 µM under white-light exposure at an irradiance of 135 mW·cm-2, applied during 30 and 60 min (light doses of 243 and 486 J·cm-2). High PDI efficiency corresponding to the inactivation process until the detection limit was observed for both PSs. The tetrasubstituted PS was the most effective, requiring the lowest concentration and the shortest irradiation time for the complete inactivation of conidia (40 µM, 30 min, 243 J·cm-2). Complete inactivation was also achieved with PS 2, but a longer irradiation time and a higher concentration (60 µM, 60 min, 486 J·cm-2) were necessary. Because of the low concentrations and moderate energy doses required to inactivate resistant biological forms such as fungal conidia, these phthalocyanines can be considered potent antifungal photodynamic drugs.

Spectral Singularities of the Photoelectric Effect in a Zinc Phthalocyanine–Fullerene (ZnPc:C70) Donor–Acceptor Blend

Spectral singularities of the ampere–watt sensitivity of photoelectric structures consisting of a transparent indium–tin oxide electrode, a photosensitive organic layer, and an aluminum electrode have been studied. The structures have been formed on a quartz glass substrate. The photosensitive layer has been vacuum-evaporated either from zinc phthalocyanine ZnPc (exhibiting donor properties) and C70 fullerene (acceptor) organic precursors or from a ZnPc:Cr70 donor–acceptor blend. Using computer simulation, the structure of absorption bands has been determined in a wide spectral range for all three above systems. This has made it possible to calculate the absorbed and reflected fractions of radiation incident on the sample and explain the singular spectral behavior of the ampere–watt sensitivity of the ZnPc:C70 blend. It has been shown that the photosensitivity of the blend reaches a maximum near the overlap of the absorption bands of donor and acceptor molecules

Evaluation of photodynamic therapy effects of novel zinc (II) phthalocyanine through a possible interaction with toll‐like receptor signaling pathway

In this work, 3‐({6‐[3‐(dimethylamino)phenoxy]hexyl}oxy)phthalonitrile (2) and the target zinc (II) phthalocyanine (3) and its ammonium derivative (3a) are synthesized, and the phototoxic effects of 3a were examined using different methods on A549 lung cancer cells. Then, the toll‐like receptor (TLR) signaling pathway was examined to determine the cell death mechanism in the A549 cancer cells. The results showed that 3a did not have noticeable cytotoxic actions on A549 cells at used concentrations. However, the compound markedly reduced the cell viability when irradiated by the red light for 5 and 15 min (LumaCare/LC‐122A/LC2020‐09‐784, Prob: LUM L [700 nm CL] [15 mW cm−2]). Additionally, Annexin V/PI staining suggested that the cells were induced apoptosis in the presence of 3a (1 μM) when irradiated with red light for 15 min. Furthermore, the expression of TLR2, TLR4, and caspase‐3 significantly increased and phospho‐nuclear factor kappa B/total nuclear factor kappa B decreased compared with that of control group (p &lt; 0.05). These results provide strong evidence that 3a is able to induce A549 cell death in a dose and a red‐light irradiation time‐dependent manner via apoptosis. Therefore, 3a might be an effective photodynamic therapy candidate for lung cancer treatment.

Novel construction of multifunctional photo-responsive and nucleic acid-triggered doxorubicin-releasing liposomes for cancer therapy

All-in-one nano theranostics integrating accurate diagnosis and combined therapy is promising for high-efficacy tumor treatment and receiving significant attention. In this study, we develop photo-controlled release liposomes with nucleic acid-triggered fluorescence and photoactivity for tumor imaging and synergistic antitumor therapy. Copper phthalocyanine as a photothermal agent is fused into lipid layers to prepare liposomes encapsulating cationic zinc phthalocyanine ZnPc(TAP)412+ and doxorubicin, followed by the modification of RGD peptide on the surface to obtain the final product RGD-CuPc:ZnPc(TAP)412+:DOX@LiPOs (RCZDL). RCZDL possesses favorable stability, significant photothermal effect, and photo-controlled release function through the characterization of physicochemical properties. It is shown that the fluorescence and ROS generation could be turned on by intracellular nucleic acid after illumination. RCZDL exhibits synergistic cytotoxicity, increased apoptosis, and significantly promoted cell uptake. Subcellular localization analysis indicates that ZnPc(TAP)412+ tends to be distributed in the mitochondria of HepG2 cells treated with RCZDL after exposure to light. The results of experiments in vivo on H22 tumor-bearing mice demonstrate that RCZDL had excellent tumor targeting, a prominent photothermal effect at the tumor sites, and synergistic antitumor efficiency. More importantly, little RCZDL has been found to be accumulated in the liver, and most were quickly metabolized by the liver. The results confirm that the proposed new intelligent liposomes provide a simple and cost-effective way for tumor imaging and combinatorial anticancer therapy.

Effect of the sol-gel condition on photostability and optical properties of alkoxy-substituted zinc phthalocyanine in the hybrid glass matrix

The series of sol-gel synthesis was prepared using different organic and inorganic acids and bases, and with different polarity of solvents, and with various concentration of the luminophore to immobilize zinc phthalocyanine to the matrix. Immobilization was achieved by coordination of zinc phthalocyanine in the axial position with isonicotinamide substituted by alkoxysilane. By using siloxane precursors, matrices of variable hydrophilicity were obtained by the sol-gel method in order to select the optimal environment for phthalocyanine immobilization. The optical properties of phthalocyanine (fluorescence and thermoluminescence) of hybrid materials were investigated. Finally, tests of material photostability under the influence of high-energy radiation were carried out with emission measurement in the ultraviolet and visible range. The aim of this study was to optimize the conditions for obtaining hybrid material containing phthalocyanine for potential application in optoelectronic systems, such as, photodiodes.

Phthalocyanine photosensitizers with bathochromic shift, of suitable brightness, capable of producing singlet oxygen with effective efficiency

• New phthalocyanine derivatives as photosensitizers were designed and synthesized. • The phthalocyanines dissolve well in common solvents without aggregation. • The phthalocyanines have improved fluorescence and optical absorption properties. • The phthalocyanines have improved photochemical properties and photostability. • The phthalocyanines can be used as photosensitizers in photocatalytic applications. In this study, novel 3-(2,3-dimethoxyphenoxy)phthalonitrile 2 and its non-peripheral tetra-2,3-dimethoxyphenoxy substituted metal-free phthalocyanine 3 compounds were synthesized. Then, the magnesium(II), zinc(II), and indium(III) acetate phthalocyanine complex derivatives ( 4-6 ) of compound 3 were synthesized using the corresponding metal salts by the template effect. The structures of novel phthalonitrile derivative 2 and its metal-free phthalocyanine compounds 3 as well as different metal-containing phthalocyanine complexes ( 4-6 ) were characterized by elemental analysis, FTIR, UV-vis, 1 H NMR, and MALDI-TOF mass spectroscopic techniques. The phthalocyanines ( 3-6 ) can dissolve well in different polar protic, polar aprotic, and non-polar solvent types without aggregation, with maximum absorption intensity and bathochromic effect. Photophysicochemical properties of the phthalocyanines ( 3-6 ) in dimethyl sulfoxide and important spectral parameter values such as molar extinction coefficient, oscillator strength, and electrical dipole strength were determined, and they were also compared with each other and with their unsubstituted counterparts. It was determined that the phthalocyanines ( 3-6 ) have suitable and sufficient fluorescence quantum yields, fluorescence lifetimes, fluorescence brightness, and other photophysical properties, as well as singlet oxygen generation, phototoxic power, and photostability properties. The phthalocyanines ( 3-6 ), particularly zinc(II) and indium(III) acetate phthalocyanines have remarkable potential for use as Type II photosensitizers for cancer therapy in photodynamic therapy. The phthalocyanines ( 3-6 ) may be promising candidates for various applications as photosensitizers for photodynamic therapy, especially in combination with fluorescent imaging.

Zinc phthalocyanine sensitized g-C3N4 photocatalyst for exceptional photocatalytic hydrogen evolution and pollutant degradation

Here in this manuscript, the high charge conductivity and exceptionally wide range soalr light absorption of metal phthalocyanines were followed for boosted photocatalysis. Graphitic carbon nitride, g-C3N4 (CN) was thermally prepared from melamine and loaded with appropriate amount of zinc phthalocyanine (ZnPc) to form ZPCN nanocomposites. The fabricated samples were used to liberate hydrogen from water and decompose 2,4-dichlorphenol (2,4-DCP) pollutant under visible-light irradiation. The optimized nanocomposite (0.5ZPCN) purchased highly accelerated photocatalysis and liberated 90 μmol H2 in 1 h in the presence of methanol as sacrificial agent. The same nanocomposite also showed 85% decomposition efficiency for the degradation of 2,4-DCP pollutant. These enhanced catalytic activity of g-C3N4 functionalized with ZnPc are attributed to the exceptional visible light absorption and effective generation of super oxide ions and holes formed after charge transfer between g-C3N4 and ZnPc as confirmed from photoluminescence, fluorescent and electrochemical characterization of the nanophotocatalysts. The charge/radical trapping experiments confirmed that super oxide anions were the main oxidizing agents in the decomposition of 2,4-DCP.

A membrane/mediator-free high-power density dual-photoelectrode PFC aptasensor for lincomycin detection in milk and chicken

Over use of lincomycin (LIN) as antibiotic in animals can lead to multiple harmful impacts to public health, thus detection of LIN at trace level in milk and chicken sample matrixes is vital. In this work, Zinc phthalocyanine nanoparticles sensitized MoS2 (ZnPc/MoS2) was firstly developed as a novel photocathode material combined with nitrogen-doped graphene-loaded TiO2 nanoparticles (TiO2/NG) as photoanode material to construct a dual-photoelectrode photofuel cell (PFC). The as-prepared membrane/mediator-free PFC achieved excellent output performance that the maximum power density (Pmax) reached 11.83 μW cm−2. Specific aptamers are adopted as LIN recognition elements, the as-proposed self-powered aptasensor for LIN exhibited a linear scope in 10−11 –10−5 mol L−1 along with a low detection limit (3S/N) of 3.33 pmol L−1. Consequently, such high-power density dual-photoelectrode PFC aptasensor may be a reassuring candidate electrochemical sensor for the detection of trace contamination in food samples.

Octafluoro-Substituted Phthalocyanines of Zinc, Cobalt, and Vanadyl: Single Crystal Structure, Spectral Study and Oriented Thin Films.

In this work, octafluoro-substituted phthalocyanines of zinc, vanadyl, and cobalt (MPcF8, M = Zn(II), Co(II), VO) were synthesized and studied. The structures of single crystals of the obtained phthalocyanines were determined. To visualize and compare intermolecular contacts in MPcF8, an analysis of Hirshfeld surfaces (HS) was performed. MPcF8 nanoscale thickness films were deposited by organic molecular beam deposition technique and their structure and orientation were studied using X-ray diffraction. Comparison of X-ray diffraction patterns of thin films with the calculated diffractograms showed that all three films consisted of a single crystal phase, which corresponded to a phase of single crystals. Only one strong diffraction peak corresponding to the plane (001) was observed on the diffraction pattern of each film, which indicated a strong preferred orientation with the vast majority of crystallites oriented with a (001) crystallographic plane parallel to the substrate surface. The effect of the central metals on the electronic absorption and vibrational spectra of the studied phthalocyanines as well as on the electrical conductivity of their films is also discussed.

NIR-Photocontrolled Aqueous RAFT Polymerization with Polymerizable Water-Soluble Zinc Phthalocyanine as Photocatalyst

In order to give an answer for the challenges of long wavelength-photocontrolled radical polymerization in aqueous solutions and to address the shortcomings of conventional near-infrared (NIR) photocatalysts (PCs) that are difficult to subject to post-treatment, we designed and synthesized a series of β-tetra-substituted water-soluble zinc phthalocyanines (β-TS-Zns) as the NIR PCs for reversible addition-fragmentation chain transfer (RAFT) polymerization successfully under irradiation with NIR (λmax = 730 nm) light at room temperature. Importantly, the NIR PCs can also be designed as polymerizable monomers and covalently loaded on the polymer chains, which are endowed with permanent NIR photocatalysis of the resultant polymers. Moreover, the polymerization can not only be carried out in water but also in phosphate buffer saline (PBS) solution, yielding polymers with controlled molar mass and narrow dispersities (Đ = 1.03-1.25). Therefore, this NIR-photocontrolled aqueous RAFT polymerization system may provide a charming strategy for possible applications in tissue engineering biomaterial in situ benefiting from the high penetration ability of NIR light.

In VitroPhotodynamic Activities of Amphiphilic Phthalocyanine‐Amino Appendedβ‐Cyclodextrin Conjugates as Efficient Schiff Base Photosensitizer

AbstractWater‐soluble phthalocyanine has been considered as a potential photosensitizer for photodynamic therapy (PDT) applications. To achieve the best efficiency of phthalocyanine in PDT, amphiphilic zinc phthalocyanine was purposely designed and synthesized by conjugation withβ‐cyclodextrin. Herein, we synthesized two novel zinc phthalocyanine derivatives connected toβ‐cyclodextrin moieties through covalent Schiff base linkage (TFP‐ZnPc/AβCD). In this procedure, aldehyde substituted phthalocyanine and amino‐appendedβ‐cyclodextrins with different length amino side chains were used. The compounds were characterized using FT‐IR,1H NMR, MALDI‐TOF, and UV‐vis. The newly designed photosensitizers did not self‐assemble in water and generated significant singlet oxygenvia1,3‐DPBF (1,3‐diphenylisobenzofuran) bleaching. Simultaneously, longer amino side chains increase1O2production efficiency. The PDT activity of the new TFP‐ZnPc/AβCD complexes was then examined on human breast cancer (MDA‐MB‐231) and fibroblast cells.In vitroresults show that PDT is more effective against cancer cells than normal cells. The new TFP‐ZnPc/AβCD could be an effective PDT drug.

Development of targeted photodynamic therapy drugs by combining a zinc phthalocyanine sensitizer with TSPO or EGFR binding groups: the impact of the number of targeting agents on biological activity.

Drug-targeted delivery has become a top priority in the world of medicine in order to develop more efficient therapeutic agents. This is important as a critical underlying problem in cancer therapy stems from the inability to deliver active therapeutic substances directly to tumor cells without causing collateral damage. In this work, zinc(II) phthalocyanine (ZnPc) was selected as a sensitizer and was linked to different targeting agents, which would be recognized by overexpressed proteins in cancer cells. As targeting agents, we first selected the two ligands (DAA1106,PK11195) of the translocator protein (TSPO) and thenErlotiniba binding group of the ATP domain of tyrosine kinase in epidermal growth factor (EGFR). ZnPc was connected via an ethylene glycol chain to either one (n = 1) or four (n = 4) targeting agents. The biological activity of these conjugates ZnPc(ligand)n was investigated on MDA-MB-231 breast human cancer cells and human hepatoma HepG2 cells, first in the dark (cytotoxicity) and then under irradiation (photodynamic therapy). The dark cytotoxicity was extremely low (IC50 ≥ 50 μM) for all of these compounds, which is a required criterion for further photodynamic application. After irradiation at 650 nm, only the conjugates bearing one targeting ligand such as ZnPc-[DAA1106]1, ZnPc-[PK11195]1, and ZnPc-[Erlo]1 showed photodynamic activity, while those linked to 4 targeting agents were inactive. Importantly, fluorescence imaging microscopy showed the colocalization of ZnPc-[DAA1106]1, ZnPc-[PK11195]1 and ZnPc-[erlo]1, at mitochondria, a result that justifies the observed photodynamic activity of these conjugates. This study first shows the impact of the number and the mode of organization of targeting agents on the ability of the sensitizer to cross the cell membrane. When zinc(II) phthalocyanine carries a single targeting agent, a significant photodynamic activity on MDA-MB-231 breast human cancer cells was measured and localization at the mitochondria was demonstrated by fluorescence imaging, thus proving the potential of the sensitizer linked to a targeting agent to improve selectivity. Another important conclusion from this study for the design of future effective PDT drugs using multivalence effects is to control the arrangement of the targeting agents in order to design molecules that will be able to pass the cell membrane barriers.

The effect of phthalocyanine's periphery on the biological activities of carbazole-containing metal phthalocyanines.

This study reports the synthesis and characterization of two new mono- and di-substituted phthalonitriles namely 4-((9H-carbazol-3-yl)oxy)-5-chlorophthalonitrile and 4,5-bis((9H-carbazol-3-yl)oxy)phthalonitrile, respectively. Cyclotetramerization of the new phthalonitriles in the presence of zinc(II) acetate resulted in related zinc(II) phthalocyanines. To study the effect of the position and number of substituents on the biological properties of the phthalocyanines, peripherally or non-peripherally tetra-substituted zinc(II) phthalocyanines bearing (9H-carbazol-3-yl)oxy groups, as well as axially di-substituted silicon phthalocyanines containing the same groups, were prepared. Since gold nanoparticles are well-known as efficient drug delivery agents, the surface of these metal nanoparticles was functionalized with all the compounds. This modification also improved the solubility of the phthalocyanines in aqueous media. In this study, the antioxidant, DNA cleavage, and toxic/phototoxic activities of the resultant nanoconjugates were examined. With a combination of metal ion and substituent (nature, number, and position) effects, the silicon(IV) phthalocyanine exhibited the highest biological properties.

Tailoring the performance of phthalocyanine-based sensor: Side chain substitution and nanofabrication

Room temperature Cl2 sensing properties of chemiresistive gas sensor based on Zinc Phthalocyanine (ZnPc) were improved by functionalizing ZnPc molecule with peripheral substitution of alkoxy side chains. The chemiresistive sensors of substituted ZnPc (ZnPcOC8) were made using spin-coated films and solution-processed nanostructures. These sensors were highly selective and sensitive towards Cl2 as compared to NH3, NO and NO2. The chlorine response kinetics of ZnPc and substituted ZnPcOC8-based sensors were investigated for Cl2 concentration range 5–1500 ppb. The ZnPcOC8-based sensors exhibit a limit of 5 ppb Cl2 with faster sensing kinetics as compared to ZnPc-based sensor. Among the three sensors, the solution-processed nanostructured-based sensor exhibits the best performance. The gas sensing mechanism of sensors has been investigated by XPS, suggesting that Zn+2 were the preferred sites for Cl2 interaction. These investigations suggest that alkoxy substitution on phthalocyanine molecules leads to development of cost effective and highly sensitive chlorine gas sensors.

Solvent effects on the photoinduced charge separation dynamics of directly linked zinc phthalocyanine-perylenediimide dyads: a nonadiabatic dynamics simulation with an optimally tuned screened range-separated hybrid functional.

Herein, we have employed a combination of the optimally tuned screened range-separated hybrid (OT-SRSH) functional, the polarizable continuum model (PCM), and nonadiabatic dynamics (NAMD) simulations to investigate the photoinduced dynamics of directly linked donor-acceptor dyads formed using zinc phthalocyanine (ZnPc) and perylenediimide (PDI), in which ZnPc is the donor while PDI is the acceptor. Our simulations aim to analyze the behavior of these dyads upon local excitation of the ZnPc moiety in the gas phase and in benzonitrile. Our findings indicate that the presence of a solvent can significantly influence the excited state dynamics of ZnPc-PDI dyads. Specifically, the polar solvent benzonitrile effectively lowers the vertical excitation energies of the charge transfer (CT) state from ZnPc to PDI. As a result, the energetic order of the locally excited (LE) states of ZnPc and the CT states is reversed compared to the gas phase. Consequently, the photoinduced electron transfer (PET) dynamics from ZnPc to PDI, which is absent in the gas phase, takes place in benzonitrile with a time constant of 10.4 ps. Importantly, our present work not only qualitatively agrees with experimental results but also provides in-depth insights into the underlying mechanisms responsible for the photoinduced dynamics of ZnPc-PDI. Moreover, this study emphasizes the importance of appropriately considering solvent effects in NAMD simulation of organic donor-acceptor systems, taking into account the distinct excited state dynamics observed in the gas phase and benzonitrile. Furthermore, the combination of the OT-SRSH functional, the PCM solvent model, and nonadiabatic dynamics simulations shows promise as a strategy for investigating the complex excited state dynamics of organic donor-acceptor systems in solvents. These findings will be valuable for the future design of novel organic donor-acceptor structures with improved performance.

Films of substituted zinc phthalocyanines as active layers of chemiresistive sensors for ammonia detection

Films of zinc phthalocyanines with alkylthio (–S(CH2)5CH3) and polyoxo (O(CH2CH2O)3CH3 and –S(CH2CH2O)3CH3) substituents, exhibiting liquid crystalline properties, were tested as active layers of chemiresistive sensors for the detection of ammonia.