Fe Phthalocyanine Research Articles

Chitosan-Based Hydrogel Functionalized with Fe(II) Phthalocyanine for Butylated Hydroxyanisole Determination.

The synthesis of functional electrode sensing materials is the key to the construction of electrochemical sensors. A new hydrogel electrode sensing material was developed by incorporating Fe(II) phthalocyanine (FePc) into chitosan-based hydrogels. The chitosan-based hydrogel plays a crucial role in dispersing FePc nanoparticles uniformly and generating a stable environment for the redox reaction of butylated hydroxyanisole (BHA) on the electrode surface. Under optimized conditions, the prepared electrochemical sensor exhibited a detection range of 0.1-30 and 30-1000 μmol/L, with a detection limit of 0.035 μmol/L (S/N = 3). Moreover, this sensor demonstrated exceptional resistance to interference and maintained its stability. These findings suggest that the developed electrochemical sensor is promising for reliable detection of BHA in real samples, highlighting the potential of combining conductive hydrogels with functionalized metal phthalocyanines for accurate and rapid BHA determination.

Front Cover: Electrochemical Evaluation of Penta‐Coordinated Fe Phthalocyanine During the Oxygen Reduction Reaction in Various Acidic Solutions (ChemElectroChem 16/2024)

Front Cover: Electrochemical Evaluation of Penta‐Coordinated Fe Phthalocyanine During the Oxygen Reduction Reaction in Various Acidic Solutions (ChemElectroChem 16/2024)

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.

Electrochemical Evaluation of Penta‐Coordinated Fe Phthalocyanine During the Oxygen Reduction Reaction in Various Acidic Solutions

AbstractIron phthalocyanine (FePc) was penta‐coordinated with pyridine ligand (Py) grafted on carbon nanotube (CNT), to form (FePc‐Py‐CNT). The complex was studied as a catalyst for the oxygen reduction reaction ORR in seven different supporting electrolytes: OH− (0.1 M), OH− (1 M), NO3− (1 M), HSO4− (1 M), ClO4− (1 M), Br− (1 M), Cl− (1 M), to unveil anion‐poisoning effects and mechanism. Through cyclic voltammetry and polarization curves in N2 and O2 saturated atmospheres, thermodynamic and kinetic data were acquired. In acid media, the formal potential Fe(III)/(II) (E0’Fe(III)/(II)) of the complex is biased to more negative potentials by the anion presence. Similar effects were observed for the onset potential (Eonset) during polarization curves for the ORR. When the ORR was performed in the presence of either ClO4−, or HSO4−, anions, Tafel analysis showed different values depending if were derived from the low or from the high overpotential regions, revealing an inner‐sphere electron transfer mechanism (ISET). The Tafel values derived from measurements in the presence of Cl− and Br− anions do not change when extracted at low or at high overpotentials evidencing an outer‐sphere reaction mechanism (OSET). Gibbs free energies were derived from poisoning tests confirming the ISET and OSET mechanisms. The poisoning effect is responsible for the immediate loss of performance for these catalysts during the ORR in acidic media.

Ab Initio Electronic, Magnetic, and Optical Properties of Fe Phthalocyanine on Cr2O3(0001).

The organic molecules adsorbed on antiferromagnetic surfaces can produce interesting interface states, characterized by charge transfer mechanisms, hybridization of molecular-substrate orbitals, as well as magnetic couplings. Here, we apply an ab initio approach to study the adsorption of Fe phthalocyanine on stoichiometric Cr2O3(0001). The molecule binds via a bidentate configuration forming bonds between two opposite imide N atoms and two protruding Cr ones, making this preferred over the various possible adsorption structures. In addition to the local modifications at these sites, the electronic structure of the molecule is weakly influenced. The magnetic structure of the surface Cr atoms shows a moderate influence of molecule adsorption, not limited to the atoms in the close proximity of the molecule. Upon optical excitation at the onset, electron density moves toward the molecule, enhancing the ground state charge transfer. We investigate this movement of charge as a mechanism at the base of light-induced modifications of the magnetic structure at the interface.

Nano-etching of carbon nanofiber surface and subsequent Fe–N–C thin film coating for enhancement of oxygen evolution reaction

The oxygen evolution reaction (OER) is involved in many electrical–chemical energy conversion systems; however, the slow reaction rate of the OER leads to a high overpotential (η) and low energy efficiency. Recently, an extremely low-η OER phenomenon was observed at a carbonaceous Fe–N-doped thin film with enriched step edges on highly oriented pyrolytic graphite and the carbon fiber surface in an alkaline electrolyte, although the activity was limited. In this study, multi-walled carbon nanotubes (MWCNTs) were used as substrates to utilize their high specific surface areas to develop an active OER catalyst. Nanoscale etching of the MWCNT surface was performed by Fe3O4 nanoparticle loading and subsequent heat treatment in an inert atmosphere, followed by acid washing. Afterwards, a carbonaceous thin film containing Fe and N was coated on the surface via sublimation, deposition, and pyrolysis of Fe phthalocyanine (Pc). A roughened surface was observed for the FePc-derived thin film coated on the nano-etched MWCNT, in contrast to the smooth surface observed for the film coated on the MWCNT without nano-etching. The combination of the nano-etching and the thin-film coating enhanced the OER, which was analyzed by parallel Tafel processes.

A broad-band investigation of ferromagnetic resonance in exchange coupled permalloy/phthalocyanine bilayer heterostructures at room temperature

The phenomenon of ferromagnet/molecule interfacial electronic hybridization enables the possibility of modifying magnetic characteristics of downscaled systems for spintronic applications. Ferromagnetic resonance (FMR) at the nanoscale level through a coplanar waveguide (CPW) over a wide frequency range is a remarkably reliable technique for investigation of the magnetic heterostructure’s interfacial properties and their feasibility in applications as spintronic devices. Here, magnetron sputtering and organic molecular beam epitaxy methods are used to fabricate the following nanoscale heterostructures: permalloy (Py)/Fe phthalocyanine (Pc), Py/ZnPc, and Py/Cr. Magnetization dynamics of the bilayer heterostructures is investigated in a CPW by studying frequency dependence (5–50 GHz) of the resonance field and linewidth with parallel and perpendicular geometries of the static applied magnetic field, thereby providing insights into possible intrinsic and extrinsic sources of FMR damping. Planar Pc molecules at the Py layer interface are found to have the potential to contribute to magnetic stabilization based on calculated magnetic parameters. This is evidenced by the larger results of surface anisotropy of the Py/MPc bilayer heterostructures induced by exchange coupling interaction at room temperature as well as the lower values of damping constant.

Molecular catalyst of Fe phthalocyanine loaded into In-based MOF-derived defective carbon nanoflowers for oxygen reduction

The complex electrochemical process of oxygen reduction reactions (ORR) poses great challenges to the development of sustainable energy alternatives such as fuel cells and metal-air batteries. The process involves the generation of defect-laden carbon nanoflower (CNF) through the calcination of indium-based metal–organic frameworks (MOFs), which are then functionalized with the molecular catalyst iron phthalocyanine (FePc) to enhance their catalytic performance. The obtained FePc@CNF is featured with a high specific surface area, numerous structural defects, and dispersed FePc molecules, which contributes to the enhanced ORR efficiency. This catalyst demonstrates an impressive onset potential of 0.966 V and a half-wave potential of 0.875 V, as well as a limit current density of 5.616 mA cm−2. Furthermore, it exhibits excellent long-term discharge stability, maintaining a current retention rate of 93.1 % after 20 h, comparable to the state-of-the-art Pt/C. Moreover, the density functional theory calculations reveal that the final step of reducing OH* to H2O and its subsequent desorption is the rate-determining step with a minimum Gibbs free energy of 0.43 eV for FePc@CNF, resulting in an enhanced ORR efficiency.

On the effects of Br−, ClO4−, NO3−anions on the oxygen reduction reaction electrocatalysis at Fe phthalocyanine modified electrodes

Fe phthalocyanine with carbon nanotubes (FePc-CNT) has been used as catalysts for ORR using the following supporting electrolyte: 0.1 M NaOH, 1 M NaOH, 1 M HNO3, 1 M HClO4, and 1 M HBr. The thermodynamic and kinetic information was acquired from cyclic voltammetry in N2 saturated media, and then polarization curves saturating with O2. The rate-determining step is modulated by the formal potential (E0’Fe(III)/(II)) in basic media, coherent with the inner sphere electron transfer mechanism. However, in strong acid electrolytes, the Tafel slope value is ∼ -0.090 V dec−1 at low overpotentials and ∼ -0.120 V dec−1 at high overpotentials indicating that a poisoning process is hampering the ORR, and causing an outer sphere electron transfer mechanism. Impedance spectroscopy and poisoning test (recovery of the activity of the catalyst in NaOH after initial use in acid) support the thesis of ion adsorption/poisoning for the low electrocatalytic activity of FePc based catalysts in acid media.

Fe phthalocyanine stabilized on phosphorous-doped multi-defective carbon nanoribbons as oxygen reduction electrocatalysts

Coordination polymers can be utilized as ideal precursors due to their ability to change their growth behavior and topological structure through solvent-induced effects. In this work, nanostrip-like crystalline particles, transformed from interchangeable indium-based coordination polymers (InOF-25/26), are treated to synthesize phosphorus-doped multi-defective carbon nanoribbons for efficiently anchoring iron phthalocyanine. The obtained FePc-Fe2P@25-CNR electrocatalyst exhibits a superior half-wave potential of 0.899 V and a large diffusion current density of 5.152 mA cm−2 in oxygen reduction reaction (ORR). Meanwhile, it also shows excellent stability in homemade Zn-air batteries with satisfactory charge/discharge durability over 100 cycles. In this case, the ORR performance can be improved by phosphating the carbon surface, reinforcing tight bonding with transition metal phthalocyanines, and inducing charge migration to increase the electrocatalysis kinetics, which is further validated by relevant theoretical calculation. This synthetic strategy combines structurally variable coordination polymers with metallomacrocyclic molecules, exploiting a feasible pathway for the preparation of high-performance electrochemical catalysts.

Hybrid organic/inorganic interface: in situ and ex situ characterization in terms of structure, morphology, electronic and magnetic properties

Organic conjugated molecules are promising media to host spin-polarized carriers, due to their weak spin relaxation mechanisms. Here, we fabricated a metal–hybrid organic–inorganic complex oxide heterostructure made of Fe–Phthalocyanine (FePc): Co(0.5 nm)/FePc(0; 0.5; 1 nm)/La0.67Sr0.33MnO3/SrTiO3 and investigated the interface structure and chemical bonding, and overall magnetic properties. Details about the Co/FePc and FePc/LSMO interfaces were obtained through X-ray photoelectron and absorption characterizations. The combined in-situ and ex-situ magnetic measurements of the heterostructure indicates the contribution of FePc and Co moments to the overall magnetic response. Moreover, these measurements indicate that the LSMO bulk magnetic properties were not canceled out by the surface treatment, but favored the formation of a magnetic dead layer. The hybrid heterostructure presents a modification of the saturation magnetization attributed to the contribution of the molecular layer. The present results are a step forward in the engineering of hybrid organic/inorganic interfaces.

Electrospun Carbon Nanofibre‐Based Catalysts Prepared with Co and Fe Phthalocyanine for Oxygen Reduction in Acidic Medium

AbstractA Pt‐free cathode catalyst is necessary for proton‐exchange membrane fuel cell (PEMFC) to enable the widespread use of these environmentally friendly energy conversion devices at affordable price. Herein, a pyrolyzed electrospun carbon nanofibre (CNF) catalyst is prepared embedded with cobalt(II) phthalocyanine and iron(II) phthalocyanine compounds to provide the transition metal N4‐macrocyclic complex‐derived sites (MNX) possessing better electrocatalytic oxygen reduction reaction (ORR) activity. The physical characterisation showed the nanofibrous structure of catalyst with rough surface texture and considerable amount of N, Fe, and Co. The D−MN4−CNF−IL−A catalyst prepared using ionic liquid as a porogen displayed the best electrocatalytic activity for O2 electroreduction proceeding via 4e− pathway in 0.5 M H2SO4 electrolyte solution with the ORR onset and half‐wave potential of 0.83 and 0.71 V vs reversible hydrogen electrode (RHE), respectively.

Iron and cobalt phthalocyanine embedded electrospun carbon nanofiber-based catalysts for anion exchange membrane fuel cell cathode

The successful implementation of renewable energy transition assumes the introduction and widespread use of zero-emission and sustainable energy conversion devices. Anion-exchange membrane fuel cell (AEMFC) is one of the appliances that meets the prescribed criteria. In this study, Fe(II) phthalocyanine and Co(II) phthalocyanine co-doped polyacrylonitrile-based electrospun carbon nanofibre (CNF) catalysts were prepared via pyrolysis. The influence of carbonisation temperature, acid leaching conditions, presence of ionic liquid (IL) as porogen, and the metal phthalocyanine content were investigated. Physical characterisation revealed the nanofibrous structure, high specific surface area, presence of Co-Nx, Fe-Nx sites, and different N-species with high oxygen reduction reaction (ORR) activity. The catalyst material with the highest ORR performance, D-MN4-CNF-IL-A, showed a half-wave potential of 857 ± 6 mV vs. reversible hydrogen electrode in 0.1 M KOH and the maximum power density value of 231 mW cm−2 when applied as a cathode catalyst in the AEMFC.

Synthesis and characterizations of Fe (II) phthalocyanine and Zn phthalocyanine on colon cancer, cervical cancer, and bacterial cells

Phthalocyanine is a safe and better biocompatible compound, and it has been used in diagnostic and cancer imaging. But the application in the treatment of colon and cervical cancer is elusive. In the present study, we have synthesized Iron (II) phthalocyanine and Zinc phthalocyanine respectively. The bonding, structure, and physical characteristics of the prepared products were analyzed and confirmed by FT-IR, XRD, SEM, EDX methods. We have also examined the anti-cancer properties of the compounds on two different cancer cells (colon cancer HCT-116 and cervical cancer HeLa) by MTT assay. The cell viability assay results showed that a noteworthy reduction in the cell viability post-treatments of Iron (II) phthalocyanine. However, treatment of Zinc phthalocyanine did not show any inhibitory action on both HCT-116 and HeLa cancer cells. We have also calculated the inhibitory concentration (IC50) post treatment of Zinc phthalocyanine and Iron (II) phthalocyanine on HCT-116 and HeLa cells. The IC50 was 30 µg/ml for HCT-116 cells treated with Iron (II) phthalocyanine, whereas it was 33 µg/ml for the HeLa cells. We have also examined the impact of Zinc phthalocyanine and Iron (II) phthalocyanine on non-cancerous cells (HEK-293), and MTT results showed that Iron (II) phthalocyanine and Zinc phthalocyanine induced no significant inhibitory action on HEK-293 cells. In addition, we have also examined the anti-fungal action of Zinc phthalocyanine and Iron (II) phthalocyanine. We have also examined the impact of Iron (II) phthalocyanine on cancer cells using DAPI staining, we have found that was a major reduction in cancer cells population, but there is no reduction in the Iron (II) phthalocyanine -treated cells. We have found that Iron (II) phthalocyanine induced significant antifungal activity against Candida albicans, whereas no significant antifungal activity was observed with Zinc phthalocyanine.

MOF-derived N-doped carbon nanosticks coupled with Fe phthalocyanines for efficient oxygen reduction

The rational design and preparation of atomic-level dispersed non-platinum catalysts to achieve efficient oxygen reduction reactions (ORR) is worth exploring for clean energy conversion and storage technology. Herein a simple self-templating strategy is demonstrated to obtain MIL-68-NH2-x series using pyridine as a surfactant to realize micron-scale to nanosized conversion. Among them, the as-prepared MIL-68-NH2-300 owns a large specific surface area and abundant pore defects after thermal treatment, which can effectively adsorb and anchor Fe phthalocyanines (FePc). In this case, MOF-derived N-doped carbon nanosticks coupled with FePc molecules (FePc@NCNS) exhibit an excellent electrocatalytic ORR activity with a positive half-wave potential (0.904 V), a large diffusion-limited current density (6.17 mA cm−2) and a high current retention after 20 h (95.7%). Furthermore, the high performance of ORR is confirmed by the relevant theoretical calculations on O2 adsorption ability. These above results will pave the way for MOF-derived carbon nanomaterials with specific morphological dimensions for high-performance energy conversion and storage.

Boosting dissolved oxygen utilization by oriented electron transfer on dual-site S-scheme heterojunction for low-H2O2-consumption photo-fenton reaction

The photo-Fenton reaction integrates the advantages of photocatalysis and Fenton process, but its catalytic efficiency for antibiotic pollution control relies heavily on the dosage of H2O2, whose production suffers from high energy input and intensive pollution. Herein, a dual-site S-scheme heterojunction is constructed by assembly of phosphate-modified TiO2 and Fe(II) phthalocyanine (FePc). Compared to the reported catalysts, this composite exhibits much higher first-order kinetic rate constant up to 0.275 min−1 in ofloxacin degradation but consumes 5–250 times less amount of H2O2. Experimental and theoretical evidences demonstrate that H2O2 molecules prefer to bind onto phosphate sites through Hbonds and donate electrons followed by its dissociation into O2−. Driven by the internal electric field, these electrons quickly flow into FePc sites to reduce adsorbed dissolved oxygen (O2) into O2−. Such dual-site configuration and oriented electron transfer eliminate the competitive reaction between O2 and H2O2. This work provides an ingenious strategy to slash H2O2 consumption by boosting O2 utilization, synergistically producing vast O2− for highly efficient pollutant degradation.

Engineering atomic Fe–N–C with adjacent FeP nanoparticles in N,P-doped carbon for synergetic oxygen reduction and zinc–air battery

FeP-900 doped with transition metals (FeP and Fe–N–C) and heteroatoms (N,P) was prepared via pyrolysis of a conjugated microporous polymer constituted by Fe–phthalocyanine and cyclotriphosphazene, in which FeP was wrapped in N,P-rich carbon matrix.

Gas Chromatographic Technique Employed for Catalytic Investigation of Novel Phthalocyanines

The primaquine substituted Fe(II) phthalocyanine (PQFePc) and Co(II) phthalocyanine (PQCoPc) catalysts were prepared by using amide linkage method. The physical and chemical properties have been investigated by FTIR, mass, UV-Vis, TGA, XRD and elemental analysis. The catalytic oxidation of benzyl alcohol was determined by PQFePc and PQCoPc complexes by varying parameters like temperature, oxidant/catalytic ratio and substance/catalyst ratio. The optimization of catalytic oxidation reaction has been effectively achieved for the determination of benzyl alcohol (Bzalc) to benzaldehyde (Bzald). The PQCoPc and PQFePc exhibited excellent catalytic behaviour for the oxidation of benzyl alcohol obtaining high yield and good selectivity.

Iron phthalocyanine derived Fe1/h-BN single atom catalysts for CO2 hydrogenation

Fe1/h-BN single atom catalysts can be successfully synthesized using heat treatment of Fe phthalocyanine decorated h-BN in an oxygen atmosphere. Selectivity toward hydrocarbons can be controlled by the presence of Fe nanoparticles.

On Curve Fitting between Heat of Formation and Entropy Measures for Fe Phthalocyanine

The second-most significant category of colorants is phthalocyanines, and copper phthalocyanine is the single colorant with the highest sales volume. Phthalocyanine colorants have historically been used as blue and green pigments for printing inks and automobile paints as well as blue/cyan dyes for textiles and paper. To determine how complex the underlying graph was, we employed Shannon’s information entropy. Certain degree-based entropies derived from topological indices were estimated. Curve fitting between calculated information entropies and Heat of formation was combined with the numerical and graphical representation of computed results. The Fe Phthalocyanine is based on topological indices, which give a comprehensive picture of potentially significant aspects that could be useful in structurally changing (FePc) for particular applications.