Exploring the Role of Excited States' Degeneracy on Vibronic Coupling with Atomic-Scale Optics.

Interactions between molecular electronic and vibrational states manifest themselves in a variety of forms and have a strong impact on molecular physics and chemistry. For example, the efficiency of energy transfer between organic molecules, ubiquitous in biological systems and in organic optoelectronics, is strongly influenced by vibronic coupling. Using an approach based on scanning tunneling microscope-induced luminescence (STML), we reveal vibronic interactions in optical spectra of a series of single phthalocyanine derivative molecules featuring degenerate or near-degenerate excited states. Based on detailed theoretical simulations, we disentangle spectroscopic signatures belonging to Franck-Condon and Herzberg-Teller vibronic progressions in tip-position-resolved STML spectra, and we directly map out the vibronic coupling between the close-lying excited states of the molecules.

Aluminum Phthalocyanine tetrasulfonate conjugated to surface-modified Iron oxide nanoparticles as a magnetic targeting platform for photodynamic therapy of Ehrlich tumor-bearing mice.

BACKGROUND: Photodynamic therapy (PDT) is a targeted treatment option for cancers that are non-responding to ordinary anticancer therapies. It involves activating a photosensitizer with a light source of a specific wavelength to destroy targeted cells and their surrounding vasculature. Aluminum phthalocyanine tetra sulfonate (AlPcS4) has gained attention as a second-generation photosensitizer for its strong absorption in the red-light region. AlPcS4 can be conjugated to magnetic iron oxide nanoparticles (IONs) to provide targeted drug delivery to the tumor cells while reducing its undesired effect on healthy tissues in other body parts. METHODS: Magnetic glutamine functionalized iron oxide nanocomposites loaded with AlPcS4 (IONs-NH2-AlPcS4) were synthesized via the co-precipitation method. The conjugate (IONs-NH2-AlPcS4) was characterized by TEM, Zeta potential, DLS, FTIR, and UV-VIS absorption spectroscopy. Furthermore, its photodynamic activity was investigated using albino mice with induced Ehrlich solid tumors. RESULTS: AlPcS4 was successfully conjugated to IONs-NH2 with a high loading efficiency of 54±2%. The synthesized conjugate exhibited a spherical shape, with 7±2 nm particle size. The In vivo experiment revealed that the albino mice with induced Ehrlich solid tumor that were treated by combined PDT and magnetic targeting conjugate exhibited significant tumor regression and notably higher levels of necrotic tissue compared to the animals in other groups. CONCLUSION: PDT mediated by magnetic targeting significantly inhibited tumor growth with minimal adverse effects, indicating its great potential as a promising strategy for solid cancer treatment.

In-situ Preparation of Iron(II)-phthalocyanine@multi-walled-CNTs Nanocomposite for Quasi-solid-state Flexible Symmetric Supercapacitors with Long Cycling Life.

The construction of supercapacitor electrode materials with exceptional performance is the crucial to the commercialisation of flexible supercapacitors. Here, a novel in-situ precipitation technique was applied for constructing iron(II)-phthalocyanine (FePc) based nanocomposite as the electrode material in quasi-solid-state flexible supercapacitors. The highly redox-active FePc nanostructures were grown in the multi-walled-CNTs (MWCNTs) networks, which shows convenient electron/electrolyte ion transport pathways along with outstanding structural stability, leading to high energy storage and long cycling life. The electrode of FePc@MWCNTs delivered a higher specific capacity than that of individual MWCNTs and FePc. The quasi-solid-state symmetric flexible device that was constructed using FePc@MWCNTs electrode demonstrated impressive performance with a maximum energy density of 29.7 Wh kg-1 and a maximum power density of 4000 W kg-1. Moreover, the device demonstrated superior durability and flexibility, as evidenced by its exceptional cyclic stability (111.3%) even after 30000 cycles at 8 A g-1. These results reveal that the FePc@MWCNTs nanocomposite prepared by this simple in-situ precipitation method is promising as electrode material for next-generation flexible wearable power sources.

Non-peripheral octasubstituted zinc(II) phthalocyanines bearing pyridinepropoxy substituents - Antibacterial, anticancer photodynamic and sonodynamic activity.

The novel non-peripheral octa-substituted zinc(II) phthalocyanines with 3- and 4-pyridinepropoxy substituents were synthesized via cyclization of substituted phthalonitriles and further characterized. Their photodynamic and sonodynamic activity were then assessed toward bacteria and cancer cells. Additionally, inhibition activity against common human enzymes was evaluated. The singlet oxygen generation (with 1,3-diphenylisobenzofuran - DPBF as an unspecific chemical quencher of singlet oxygen) were measured under light irradiation, whereas under ultrasounds (1 MHz, 3 W) the stability of DPBF in the presence of sensitizer was evaluated. Both phthalocyanines revealed high photostability in DMSO and moderate in DMF, whereas the sonostability in DMF was moderate. Calculated light-induced singlet oxygen generation quantum yields were similar for both compounds and oscillated around 0.33 in DMF and 0.67 in DMSO. Sonodynamic manner revealed moderately high DPBF decomposition upon 1 MHz. Significant bacterial reduction was noted in both photodynamic and sonodynamic manner, reaching >3 log reduction against MRSA and S. epidermidis. Both compounds showed ca. 50 % viability reduction toward hypopharyngeal tumor (FaDu). Moreover, up to 60 % viability reduction was observed in squamous cell carcinoma (SCC-25). In summary, this molecular building of the efficient phthalocyanine-based sensitizer is a potential therapeutic for photodynamic and sonodynamic applications.

Phthalocyanine derivative attenuates TNF-α production in macrophage culture and prevents alveolar bone loss in experimental periodontitis.

AIM: This study investigated the activity and mechanism of action of the iron tetracarboxyphthalocyanine (FeTcPc) on tumor necrosis factor alpha (TNF-α) production and its impact on experimental periodontitis. METHODS: RAW 264.7 macrophages were treated with FeTcPc, activated with lipopolysaccharide (LPS) at 10 ng/mL, and the TNF-α levels were measured, as well as the nuclear factor kappa B (NF-κB) activation. Subsequently, a mouth gel containing 1% FeTcPc was topically administered to the gingival tissue of mice with periodontitis-induced ligatures. Bone loss and the gene expression of Tnfα, p65 (NF-κB), and receptor-activating nuclear factor kappa B ligand (Rankl) were quantified in gingival tissue. Finally, the systemic toxicity of FeTcPc was estimated in Galleria mellonella larvae. RESULTS: In an activated RAW 264.7 macrophage culture, 100 µM FeTcPc reduced TNF-α release and NF-κB activation. Regarding experimental periodontitis, topical application of mouth gel containing 1% FeTcPc blocked alveolar bone loss. Additionally, 1% FeTcPc reduced the expression of Tnfα, p65 (NF-κB), and Rankl in gingival tissue. Finally, administration FeTcPc at doses ranging from 1 to 1000 mg/kg did not cause acute systemic toxicity in G. mellonella. CONCLUSION: Overall, we demonstrated the potential of mouth gel containing FeTcPc as a therapeutic strategy for managing osteolytic inflammatory disorders, such as periodontitis.

A new silicon phthalocyanine dye induces pyroptosis in prostate cancer cells during photoimmunotherapy.

Photoimmunotherapy (PIT) combines the specificity of antibodies with the cytotoxicity of light activatable photosensitizers (PS) and is a promising new cancer therapy. We designed and synthesized, in a highly convergent manner, the silicon phthalocyanine dye WB692-CB2, which is novel for being the first light-activatable PS that can be directly conjugated via a maleimide linker to cysteines. In the present study we conjugated WB692-CB2 to a humanized antibody with engineered cysteines in the heavy chains that specifically targets the prostate-specific membrane antigen (PSMA). The resulting antibody dye conjugate revealed high affinity and specificity towards PSMA-expressing prostate cancer cells and induced cell death after irradiation with red light. Treated cells exhibited morphological characteristics associated with pyroptosis. Mechanistic studies revealed the generation of reactive oxygen species, triggering a cascade of intracellular events involving lipid peroxidation, caspase-1 activation, gasdermin D cleavage and membrane rupture followed by release of pro-inflammatory cellular contents. In first in vivo experiments, PIT with our antibody dye conjugate led to a significant reduction of tumor growth and enhanced overall survival in mice bearing subcutaneous prostate tumor xenografts. Our study highlights the future potential of the new phthalocyanine dye WB692-CB2 as PS for the fluorescence-based detection and PIT of cancer, including local prostate tumor lesions, and systemic activation of anti-tumor immune responses by the induction of pyroptosis.

Direction Modulation of Intramolecular Electric Field Boosts Hole Transport in Phthalocyanines for Perovskite Solar Cells.

Tuning the strength of intramolecular electric field (IEF) in conjugated molecules has emerged as an effective approach to boost charge transfer. While direction manipulation of IEF would be a potential way that is still unclear. Here, we leverage the control of peripheral substituents of conjugated phthalocyanines to chemically tune the spatial orientation of IEF. By analyzing the spatial swing of side chains using the Kolmogorov-Arnold representation and least squares algorithm, a comprehensive mathematical-physical model has been established. This model enables rapid evaluation of the IEF and maximum hole transport performance induced by spatial swings. The champion phthalocyanine as dopant-free hole transport material in perovskite solar cell realizes a record performance of 23.41%. Greatly device stability is also exhibited. This work affords a new way to enhance hole transport capabilities of conjugated molecules by optimizing their IEF vector for photovoltaic devices.

Interface Engineering by Unsubstituted Pristine Nickel Phthalocyanine as Hole Transport Material for Efficient and Stable Perovskite Solar Cells.

Lead halide perovskite solar cells (PSCs) have been rapidly developed in the past decade. With the development of a PSC, interface engineering plays an increasingly important role in maximizing device performance and long-term stability. We report a simple and effective interface engineering method for achieving improvement of PSCs up to 20% by employing unsubstituted pristine nickel phthalocyanine (NiPc). Thermal annealing of NiPc improves the interface between NiPc and perovskite because of the incorporation of NiPc molecules into the perovskite grain boundaries, which creates improvements in hole extraction from the perovskite absorber layer, as evidenced by time-resolved photoluminescence measurements. This significantly improves the charge transfer and collection efficiency, which are closely related to the improvement of the interface between perovskite and NiPc.

Trifluoromethyl-pyrrolidone phthalocyanine nanoparticles for targeted lipid droplet imaging and in vitro photodynamic therapy in breast cancer cells.

Lipid droplets (LDs) serve as vital subcellular organelles, crucial for the maintenance of lipid and energy homeostasis within cells. Their visualization is of significant value for elucidating the intricate interactions between LDs and other cellular organelles. Despite the importance of LDs, the literature on the utilization of phthalocyanine-based photosensitizers for targeted LD imaging and two-photon imaging-guided photodynamic therapy (PDT) remains sparse. In this study, we have designed and synthesized trifluoromethyl-pyrrolidone silicon phthalocyanine (PyCF3SiPc). To enhance the water solubility of PyCF3SiPc and improve its tumor cells accumulation, we employed 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000] (DSPE-mPEG2000) as a nanocarrier, thereby formulating DSPE@PyCF3SiPc nanoparticles. Our in vitro experiments in MCF-7 cells demonstrated that DSPE@PyCF3SiPc selectively targets and visualizes LDs, offering a reliable tool for tracking their dynamic movement. Moreover, DSPE@PyCF3SiPc demonstrates considerable phototoxicity against MCF-7 cells subjected to PDT underscoring its potential as an effective therapeutic agent. In conclusion, DSPE@PyCF3SiPc presents itself as a promising novel probe for the dual purpose of monitoring the dynamic movement of LDs and guiding imaging-assisted PDT. The development of this nanoparticle system not only advances our understanding of LD biology but also paves the way for innovative therapeutic strategies in oncology.

Electrodeposition of Manganese (III) Phthalocyanine/ Reduced Graphene Oxide for Asymmetric Supercapacitor Devices.

In this study, two novel tetra-substituted manganese (III) phthalocyanines bearing 9H-Carbazol-2-yloxy groups on peripheral or non-peripheral positions were prepared and used for modification of reduced graphene oxide by applying a simple one-step electrodeposition technique for the first time. The manganese (III) phthalocyanines (1 and 2) were electropolymerized and graphene oxide was electrochemically converted into reduced graphene oxide simultaneously. Subsequently, an rGO-MnPc hybrid structure was formed directly on the NiF electrode (substrate) via layer-by-layer assembly. Additionally, the effect of substituent position on the charge storage capacity of the prepared hybrid capacitive candidates was investigated. The fabricated hybrid electrodes exhibited remarkable electrochemical performance due to the combination of manganese (III) phthalocyanines and reduced graphene oxide. The NiF/rGO2-2 electrode exhibited the highest specific capacitance (512.4 F g-1) at 0.5 A g-1 and the remained specific capacitance was obtained 88.1% after 5000 consecutive charge-discharge cycles. An asymmetric supercapacitor (ASC) was constructed from rGO2-2 as the positive electrode and rGO as the negative electrode with a working potential of 1.5 V. The as-prepared device delivered a specific energy of 17.4 Wh kg-1 at 350 W kg-1. Hence, manganese (III) phthalocyanine-reduced graphene oxide electrodes can be considered outstanding materials for energy storage applications in the future.

Revealing the Impact of Aging on Perovskite Solar Cells Employing Nickel Phthalocyanine-Based Hole Transporting Material.

The enhancement of the photovoltaic performance upon the aging process at particular environment is often observed in perovskite solar cells (PSCs), particularly for the devices with 2,2',7,7'-tetrakis(N,N-di(4-methoxyphenyl)amino)-9,9'-spirobifluorene (spiro-OMeTAD) as hole transporting material (HTM). In this work, for the first time the effect of aging the typical n-i-p PSCs employing nickel phthalocyanine (coded as Bis-PF-Ni) solely as dopant-free HTM is investigated and as an additive in spiro-OMeTAD solution. This study reveals that the prolong aging of these devices at dry air condition (RH = 2%, 25 °C) is beneficial for the improvement of their performances. Various bulk and surface characterization techniques are utilized to understand the factors behind the spontaneous efficiency enhancement of the devices after storage. As a result, the changes in properties of the Bis-PF-Ni layer are observed and at perovskite/Bis-PF-Ni interface, which ultimately improves the charge transport and reduces non-radiative recombination. In addition, the devices with Bis-PF-Ni HTM reveal enhanced long-term ambient and thermal stability compared to the PSCs based on doped spiro-OMeTAD.

A Fully Edible Transistor Based on a Toothpaste Pigment.

Edible electronics is emerging in recent years motivated by a diverse number of healthcare applications, where sensors can be safely ingested without the need for any medical supervision. However, the current lack of stable and well-performing edible semiconductors needs to be addressed to reach technological maturity and allow the surge of a new generation of edible circuits. In the quest for good-performing edible semiconductors, this study has explored the possibility of considering materials that are not regulated for intentional ingestion, yet are daily swallowed with no adverse reactions, such as pigments contained in toothpaste. This work first elaborates on the basis of inadvertent ingestion data to estimate the quantity of daily ingested Copper(II) Phthalocyanine (CuPc), a whitening pigment and well-known organic semiconductor. Subsequently, CuPc is employed in the first demonstration of fully edible electrolyte-gated transistors operating at low voltage (<1 V), displaying good reproducibility and stable performance for over a year. The results indicate that, with the daily ingested quantity of CuPc from toothpaste, more than 104 edible transistors can be realized, thus paving the way to edible circuits, a critical component of future edible electronic systems.

NIR laser-activated phthalocyanine loaded lipid nanoparticles targeting M2 macrophage for improved photoacoustic imaging-guided photothermal therapy.

The development of novel phototheranostic agents with significant potential in bioimaging-guided therapy is highly desirable for precise tumor therapy. Herein, NIR laser-activated ruthenium phthalocyanine (PcRu) loaded sub-30 nm targeting lipid nanoparticles (α-PcRu-NPs) were fabricated for photoacoustic imaging (PAI)-guided photothermal therapy (PTT). Due to the formation of J-type aggregation of PcRu in the core of the nanostructure, the α-PcRu-NPs exhibited high stability, efficient NIR absorption, reduced singlet oxygen generation, high photothermal activity, and intense photoacoustic signal. With the M2 macrophage target peptide (M2pep) modification and small size of α-PcRu-NPs, in vivo evaluations reveal that α-PcRu-NPs can specifically target and deeply penetrate the tumor foci. Under a high contrast PAI guidance with α-PcRu-NPs (744 nm, 0.35 µW), it also realizes superior photothermal therapy (PTT) for breast cancer under 670 nm laser irradiation (0.5 W/cm2). The prominent therapeutic efficacy of α-PcRu-NP-based PTT not only directly kills tumor cells, but also enhances the immune response by promoting dendritic cell maturation and increasing cytotoxic T cell infiltration. Thus, this work broadens the applications of phthalocyanine derivatives as phototheranostics in the PAI-guided PTT field.

Mononuclear high-spin iron(III) phthalocyanines.

2,9(or 10),16(or 17), 23(or 24)-Tetradecyloxycarbonylphthalocyaninatoiron, FeTDPc, and 2,3,9,10,16,17,23,24-octadecyloxycarbonylphthalocyaninatoiron, FeODPc, were synthesized and characterized. These compounds seem to be in trivalent iron high-spin state in solvents such as chloroform, dichloromethane, benzene, and chlorobenzene, although their counter anion could not be detected by elemental analyses. They react with strong bases such as pyridine and imidazoles to form their mono- and subsequently their di-base complexes with formation constant of >106 and < 200 dm3 mol-1, respectively, in dichloromethane at 20 °C. The resultant mono-adducts appear to be trivalent iron low-spin while the di-base adducts are bivalent iron low-spin state complexes. The addition of ca. 10-30 equivalent of tetrabutylammonium-chloride or -bromide (electrolyte) to the solution containing FeTDPc or FeODPc, causes their spin-state change from iron(III) high to low-spin state. In a solid power state, however, both FeTDPc and FeODPc exist as a mixture of high-spin iron(III)- and intermediate-spin iron(II) species. Strangely, when these compounds are dissolved in polystyrene, i.e. each molecules are isolated from each other, the signals originated from the iron(II) component disappear.

Zinc Phthalocyanine Core-First Star Polymers Through Nitroxide Mediated Polymerization and Nitroxide Exchange Reaction.

Nitroxide-mediated polymerization (NMP) and nitroxide exchange reaction (NER) are very efficient methodologies that require only suitable alkoxyamine derivatives and create different polymeric architectures in a controlled manner. Herein, the synthesis of star polymers containing TEMPO-substituted symmetric zinc phthalocyanine (ZnPc) is presented via NMP and NER. Moreover, linear polymer formation is conducted in a single arm on TEMPO-substituted asymmetric ZnPc to elucidate the properties of star polymers. All linear and star polymers are characterized by FT-IR, UV-vis, fluorescence, GPC, NMR, and EPR techniques. The results show that the proposed reactions are capable of forming controlled star-shaped polymers. The increasing arm number (from a single to four arms) results in variable dispersity values (D) (1.2-3) due to different arm lengths, especially in NMP. However, this difficulty has been overcome via NER, and star polymers have been successfully synthesized with relatively low molecular weight (30 K > 10 K) and low dispersity (1.2-1.9). The results clearly indicate that while styrene and 4-vinyl benzyl chloride monomers are introduced to the structure equally, star polymers with phthalocyanine can be synthesized in a controlled manner, and their quarternized derivatives have the potential to be effective as photoactive agents in photodynamic therapy.

Recent Advances in Phthalocyanine-Based Hybrid Composites for Electrochemical Biosensors.

Biosensors are smart devices that convert biochemical responses to electrical signals. Designing biosensor devices with high sensitivity and selectivity is of great interest because of their wide range of functional operations. However, the major obstacles in the practical application of biosensors are their binding affinity toward biomolecules and the conversion and amplification of the interaction to various signals such as electrical, optical, gravimetric, and electrochemical signals. Additionally, the enhancement of sensitivity, limit of detection, time of response, reproducibility, and stability are considerable challenges when designing an efficient biosensor. In this regard, hybrid composites have high sensitivity, selectivity, thermal stability, and tunable electrical conductivities. The integration of phthalocyanines (Pcs) with conductive materials such as carbon nanomaterials or metal nanoparticles (MNPs) improves the electrochemical response, signal amplification, and stability of biosensors. This review explores recent advancements in hybrid Pcs for biomolecule detection. Herein, we discuss the synthetic strategies, material properties, working mechanisms, and integration methods for designing electrochemical biosensors. Finally, the challenges and future directions of hybrid Pc composites for biosensor applications are discussed.

Quantum Chemical Stability Analysis of Phthalocyanine Metal One-Dimensional Polymers with Bidentate Ligands.

The combination of metal-phthalocyanine complexes and axially coordinated organic molecules into polymer chains presents a significant challenge in the synthesis of hybrid materials. A calculated structure for one-dimensional coordinate polymers with N-donor ligands using ab initio (PM6) and DFT (LanL2Dz) methods is presented. DFT methods have shown that there is a linear, one-dimensional structure without distorted geometry for the two bipyridine ligands. The components of the proposed polymers consist of square-planar Zn complexes of phthalocyanine (PcZn) connected via bridging ligands (L). Electronic properties of the monomer PcZnL of zinc phthalocyanine with bidentate ligands have been analyzed using calculations based on density functional theory (B3LYP6-31G(d,p)). Molecular orbital calculations show that this connection between the metallomacrocycle and the conjugated ligand results in a small energy gap, promising molecularly active materials as conductors. The crystallographic reports indicate that obtaining this kind of polymer with the participation of Pc Zn and bidentate ligands is possible.

Hierarchical Nanostructures of Iron Phthalocyanine Nanowires Coated on Nickel Foam as Catalysts for the Oxygen Evolution Reaction.

In this paper, iron phthalocyanine nanowires on a nickel foam (FePc@NF) composite catalyst were prepared by a facile solvothermal approach. The catalyst showed good electrochemical oxygen evolution performance. In 1.0 M KOH electrolyte, 289 mV low overpotential and 49.9 mV dec-1 Tafel slope were seen at a current density of 10 mA cm-2. The excellent electrochemical performance comes from the homogeneous dispersion of phthalocyanine nanostructures on the surface of the nickel foam, which avoids the common agglomeration problem of such catalysts and provides a large number of active sites for the OER reaction, thus improving the catalytic performance of the system.

On physical analysis of phthalocyanine iron (II) using topological descriptor and curve fitting models.

A new area of applied chemistry called chemical graph theory uses combinatorial techniques to explain the complex interactions between atoms and bonds in chemical systems. This work investigates the use of edge partitions to decipher molecular connection patterns. The main goal is to use topological indices that capture important topological features to create a connection between the thermodynamic properties and structural characteristics of chemical molecules. We specifically examine the complex web of atoms and links that make up the Fe phthalocyanine chemical graph. Moreover, our study demonstrates a relationship between the calculated topological indices and the thermodynamic properties of Fe phthalocyanine (Phthalocyanine Iron (II)). This work offers insight into the thermodynamic consequences of molecule structures. It advances the subject of chemical graph theory, providing a useful perspective for future applications in catalysis and materials science.

Synthesis and comparison of the performance of two different water-soluble phthalocyanine based electrochemical biosensor.

Herein, a comparative study between novel water-soluble phthalocyanine-based biosensors was performed for the application of glucose sensing. For this purpose, two different copper (II) and manganese (III) phthalocyanines and their water-soluble derivatives were synthesized, and then their role as a supporting material for enzyme immobilization was evaluated by comparing their sensor performances. Two different phthalocyanine (AP-OH2-MnQ (MnPc) and AP-OH2-CuQ (CuPc)) were tested using electrochemical biosensor with immobilized glucose oxidase (GOx). To the best of our knowledge, the related water-soluble phthalocyanine-based glucose biosensors were attempted for the first time, and the developed approach resulted in improved biosensor characteristics. The constructed biosensors GE/MnPc/GOx and GE/CuPc/GOx showed good linearity between 0.003-1.0 mM and 0.05-0.4 mM, respectively. The limit of detection was estimated at 0.0026 mM for the GE/MnPc/GOx and 0.019 mM for the GE/CuPc/GOx. KMapp and sensitivity values were also calculated as 0.026 mM and 175.043 µAmM-1 cm-2 for the GE/MnPc/GOx biosensor and 0.178 mM and 117.478 µAmM-1 cm-2 for the GE/CuPc/GOx biosensor. Moreover, the fabricated biosensors were successfully tested to detect glucose levels in beverages with high recovery results. The present study shows that the proposed water-soluble phthalocyanines could be a good alternative for quick and cheap glucose sensing with improved analytical characteristics.