Zinc Tetra Research Articles

Synthesis, molecular docking, drug‐likeness analysis, and ADMET prediction of nickel and zinc tetraphenyl‐porphyrin complexes as possible antioxidant agents

AbstractNickel tetraphenyl‐porphyrin (NiTPPH₂) and zinc tetra(4‐methophenyl)‐porphyrin (ZnTPPH₂(p‐methyl)) were successfully synthesized and characterized using 1H NMR spectroscopy. Their antioxidant activities and interactions with the superoxide anion radical () were evaluated using cyclic voltammetry. Remarkably, NiTPPH₂ displayed superior antioxidant activity with an IC50 value of 54.57 μg mL−1, significantly outperforming α‐tocopherol (IC50 = 353.27 μg mL−1), indicating its potential as a potent antioxidant. Binding free energy calculations demonstrated that electrostatic interactions predominantly govern the binding, with values of −23.47 kJ mol−1 for NiTPPH₂ and −22.50 kJ mol−1 for ZnTPPH₂(p‐methyl). These values suggest robust binding affinities with . Quantum chemical parameters, obtained through density functional theory (DFT), showed a strong correlation with experimental results, validating the computational approach. Additionally, ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) and drug‐likeness assessments, alongside molecular docking studies, highlighted favorable pharmacokinetic profiles and binding affinities. These findings underscore the potential of NiTPPH₂ and ZnTPPH₂(p‐methyl) as promising candidates for antioxidant therapy, exhibiting drug‐like properties and favorable pharmacokinetics. This research advances the understanding of these porphyrin derivatives and their application in the development of novel antioxidant therapeutics.

High-Performance Anode Material Based on Zinc Naphthalocyanine/Graphene Composite.

Transition metal oxides are a potential anode material owing to their high theoretical capacity. Nonetheless, their large volume changes and low electrical conductivities lead to poor cycling performance and rate capabilities. In this article, an effective strategy is proposed and developed for preparing a ZnO/N-doped graphene composite (ZnNc/GO-5). The key point of this strategy is to use zinc tetra tert-butyl-naphthalocyanine (ZnNc) as a codoped source of N atoms and zinc ions, and graphene oxide (GO) which is combined with ZnNc by π-π deposition as a carbon matrix. After calcination, ZnO microcrystals coated with N-doped graphene are obtained. The unique features of the composite and synergistic effect between N-doped reduced graphene oxide and ZnO microcrystals enable good electrochemical performance by the composites when used in lithium-ion batteries. As an anode material, the as-synthesized ZnNc/GO-5 composite delivers a high first capacity of 1942.9 mAh g-1 and excellent cyclic stability of 861.4 mAh g-1 after 150 cycles at 100 mA g-1. This strategy may offer a new method of designing the anode materials of lithium-ion batteries and promote the practical use of organic molecules in next-generation lithium-ion batteries.

Porphyrin Supramolecular Nanoassembly/C3N4 Nanosheet S-Scheme Heterojunctions for Selective Photocatalytic CO2 Reduction toward CO.

The photocatalytic reduction of CO2 with H2O into valuable chemicals is a sustainable carbon-neutral technology for renewable energy; however, the photocatalytic activity and product selectivity remain challenging. Herein, an S-scheme heterojunction photocatalyst with superior CO2 photoreduction performance─porous C3N4 (CN) nanosheets anchored with zinc(II) tetra(4-cyanophenyl)porphyrin (ZnTP) nanoassemblies (denoted as ZnTP/CN)─was designed and prepared via a simple self-assembly process. The constructed ZnTP/CN heterojunction had rich accessible active sites, improved CO2 absorption capacity, and high charge carrier separation efficiency caused by the S-scheme heterojunction. As a result, the obtained ZnTP/CN catalyst exhibited considerable activity for photocatalytic CO2 reduction, yielding CO with a generation rate of 19.4 μmol g-1·h-1 and a high selectivity of 95.8%, which is much higher than that of pristine CN nanosheets (4.53 μmol g-1·h-1, 57.4%). In addition, theoretical calculations and in situ Fourier transform infrared spectra demonstrated that the Zn sites in the porphyrin unit favor CO2 activation and *COOH formation as well as CO desorption, thereby affording a high CO selectivity. This work provides insight into the design and fabrication of efficient S-scheme heterostructure photocatalysts for solar energy storage.

Plasmon-enhanced dye-sensitized solar cells through porphyrin-silver nanoparticle hybrid structures: Experimental and computational studies

Surface plasmon resonance of silver nanoparticles (Ag NPs) was used to improve light absorption of porphyrins in plasmon-enhanced porphyrin-sensitized solar cells (PSSCs). Porphyrins with different substituents consisting –H, -Me, -MeO, –F, -Cl, -Br, –CO2H, –SO3H, –NO2, and –NH2 were used to study the effect of the interactions between photoactive dye molecules and plasmonic Ag NPs on the performance of PSSCs. The obtained results revealed that zinc tetra(4-carboxyphenyl)porphyrin and zinc tetra(4-aminophenyl)porphyrin have made the biggest impact on the performance of plasmon-enhanced PSSCs. Computational studies were done to study the electronic properties of porphyrin molecules with electron-withdrawing and electron-donating substituents interacted with Ag NPs. The theoretical studies confirmed that the electronic nature of substituents of porphyrins has a considerable effect on the electronic properties of porphyrin-AgNPs systems. In continue, [email protected] core-shell NPs were prepared to overcome the challenge of corrosion of Ag plasmonic nanoparticles. The results showed that using [email protected] systems, in many cases, the performance of PSSCs is increased relative to corresponding porphyrins but is decreased relative to porphyrin-AgNPs systems.

Photoinduced Electron Transfer Reactions of Water Soluble Porphyrins in Zeolite Environment.

Excited state interactions of zeolite adsorbed porphyrins have been investigated by steady state luminescence quenching technique with certain antioxidants such as reduced glutathione, ascorbic acid and L-cysteine. The zeolite supported porphyrins, meso-tetra (N-methyl-4-pyridyl) porphyrin (H2TMPyP4+) and zinc tetra(N-methyl-4-pyridyl) porphyrin (ZnTMPyP4+) were prepared and characterized by various techniques such as Diffuse Reflectance Spectra (DRS), Scanning Electron Microscope (SEM), powder X-Ray Diffraction (XRD) and BET surface area. The interaction of zeolites with porphyrins are shown to increase the lifetime of the singlet excited state of porphyrins and decays are biphasic in nature. The splitting of the emission band of porphyrins occurs in 1:1 glycerol: water solution due to the changes in the dielectric of the solvation sphere associated with porphyrin. The Stern-Volmer plots of I0/I vs quencher concentration [Q] were linear in the whole range of [Q] used. These studies revealed the effective quenching for zinc porphyrin compared to free base porphyrin. The effect of quenchers and zeolite acidity has also been studied and the quenching rate constant (kq) is found in the order of 109M-1s-1. The quenching reaction obeys Rehm-Weller Equation and is shown to be due to thermodynamically favoured electron transfer from quenchers to the excited singlet state of porphyrins (reductive quenching).

Stable Amperometric Sensor Based on Novel Polymeric Zinc Phthalocyanine Film for the Nanomolar Detection of Ammonia

Novel zinc tetra [4-[2-(1H-benzimidazol-2-yl) phenoxy]] phthalocyanine (ZnTBImPc) was prepared in a pure state and good yield. The characterization of the ligands and complex were done by combination of techniques like elemental analysis, UV-Visible, FT-IR, Mass, TGA, XRD and electrochemical techniques. The benzimidazole moiety of ZnTBImPc undergoes electropolymerization and the polymeric layer deposits on glassy carbon surface. The polymeric film interface was characterized and used for the voltammetric sensing of ammonia which showed linear characteristics in 0.1 to 1.0 µM range. The LOD was 0.03 µM with sensitivity of 237.25 µAµM-1cm-2. The efficiency and sensitivity of ammonia oxidation at the poly(ZnTBImPc) was compared with the composite hybrid electrode of poly(ZnTBImPc) and carbon nanoparticle (CNP). The amperometric sensing of ammonia showed linear behaviour in the 0.05 to 0.5 µM range. The RDE experiment revealed that the number of electrons involved in the ammonia oxidation is nearly 3. The polymeric electrode was subjected to the interference studies to evaluate the selectivity of the fabricated electrode and found that the co-existing molecules did not show interference during the detection of ammonia.

Zinc porphyrin/mesoporous titania thin film electrodes: a hybrid material nanoarchitecture for photocatalytic reduction.

In this work, photocatalytic reduction of methyl viologen is achieved using zinc tetra(4-N-methylpyridyl)porphine (ZnP) functionalized mesoporous titania thin films (MTTF). Metalloporphyrins are the core of natural systems that harvest energy from the sun. Thus, a bioinspired approach is used, taking advantage of ZnP sensitizing capabilities and MTTF organized structure.

Oxygen-independent free radical generation mediated by core-shell magnetic nanocomposites synergizes with immune checkpoint blockade for effective primary and metastatic tumor treatment

Advanced or metastatic tumor treatment is a long-lasting problem that leads to high mortality. Photodynamic therapy (PDT) has emerged as a promising clinical therapeutic strategy with the ability of destroying local tumors and initiating systemic anti-tumor immune responses for metastasis inhibition. However, the efficacy is typically limited by tumor hypoxia, aggregation caused self-quenching of classic photosensitizers (PSs), and intrinsic or adaptive immune resistance that mediated by cellular and molecular immunosuppressive components. Here, we designed an oxygen-independent photosensitizer by core-shell magnetic nanocomposites (MNCs), with functionalized iron oxide nanoclusters as the core and coordination polymerization of Zinc Tetra (N-methyl-4-pyridyl) porphyrin (ZnTMPyP) as the shell. MNCs PDT induced persistent free radical generation via facilitating an effective electron-hole separation, polarized macrophages to pro-inflammatory M1 phenotype, and activated systemic antitumor immunity. Nevertheless, adaptive immune resistance occurred simultaneously, characterized by highly increased PD-L1 expression on tumor cells, dendritic cells (DCs) and macrophages. As a result, combined use of MNCs PDT with checkpoint blockade effectively suppressed well-established primary tumors as well as tumor metastasis via a ‘trident’ modality, including persistent free radical generation in both normoxic and hypoxic conditions for direct tumor destruction, enhanced frequency of tumor infiltrating-lymphocytes (TILs) and modified tumor immunosuppressive microenvironment with reduced immunosuppressive cells and PD-L1 blockade. We also explore the underlying mechanisms of metastasis inhibition according to the transcriptome expression profiling of lung tissues, which revealed that the ‘trident’ modality altered numerous genes mainly related to immuno-activation and cancer associated signaling pathways. We expect the expanded use of this platform for various types of cancer malignancy.

Amperometric determination of dopamine based on an interface platform comprising tetra-substituted Zn2+ phthalocyanine film layer with embedment of reduced graphene oxide

The present study of ectrochemical zinc tetra [4-{2-[(E)-2-phenylethenyl]-1H-benzimidazol-1-yl}] phthalocyanine (Zn(II)TPEBiPc) film layer embedded reduced graphene oxide (rGO) based sensor was used for the determination of dopamine (DA) is reported. We present reduced graphene oxide with substituted zinc(II)phthalocyanine immobilized composite sensor in comparison with the phthalocyanine film layer onto a thin surface of the glassy carbon electrode (GCE). The composite hybrid material was prepared and characterized by spectral and electroanalytical spectroscopy. The substituted zinc(II)phthalocyanine with reduced graphene oxide composite modified electrode shows more competitive results in the detection of Dopamine molecule. The electrochemical behavior was investigated using cyclic voltammetry, differential pulse voltammetry. The amperometry sensor shows an excellent analytical performance in the concentration range 20 nM to 1.0 μM with detection limit (LOD) of 06 nM and sensitivity of 2.8784 μAμM–1 cm−2 respectively for GCE/rGO-Zn(II)TPEBiPc and GCE/Zn(II)TBPc. The rGO-Zn(II)TPEBiPc modified electrode exhibited better performance. Furthermore, the composite sensor demonstrated long-term storage stability, good repeatability and reproducibility. The practical applicability of the sensor has been assessed in pharmaceutical drugs. The illustrated method efficiently bridges the very good physicochemical properties of reduced graphene oxide with rich redox chemistry of Zinc(II)phthalocyanine.

Radioiodinated Persistent Luminescence Nanoplatform for Radiation-Induced Photodynamic Therapy and Radiotherapy.

Radionuclide with Cerenkov radiation (CR) can serve as an internal excitation source to activate photosensitizers for photodynamic therapy (PDT) in deep tumor. However, the low efficiency of CR limits its therapeutic efficacy. A 131 I labeled zinc tetra(4-carboxyphenoxy) phthalocyaninate (ZnPcC4) conjugated Cr3+ -doped zinc gallate (ZnGa2 O4 :Cr3+ , ZGCs) nanoplatform (131 I-ZGCs-ZnPcC4) is developed for radiotherapy (RT) and radiation-induced PDT. 131 I can not only activate ZGCs for long-lasting luminescence via both Cerenkov luminescence (CL) and ionizing radiation, which further continuously activate photosensitizer ZnPcC4 for PDT, but also can directly kill cancerous cells. This 131 I-ZGCs-ZnPcC4 exhibits excellent tumor inhibition both in vitro and in vivo. Combining self-activated PDT and RT, it is believed that the 131 I-ZGCs-ZnPcC4 can greatly benefit the deep tumor therapy.

Framework induced deformation modulates the photophysical properties of ZnTetra(4-pyridyl)porphyrin incorporated within a new metal organic framework, RWLAA-1

Porphyrin based metal organic frameworks (MOFs) have provided a broad platform through which a wide variety of light harvesting applications have been developed. Of particular interest within light harvesting MOFs containing porphyrin chromophores is the extent to which the both environment of the porphyrin and the porphyrin conformation modulate the photophysical properties. With this in mind, a new MOF (RWLAA-1) has been synthesized based on zinc cations linked by zinc(ii) tetra(4-pyridyl)porphyrin (ZnTPyP) and benzene tricarboxylate (H3BTC) linkers in which the porphyrin exhibits significant conformational distortions that have a profound effect on the photophysics of the material including bathochromic shifts in both the optical (Soret and visible bands) and emission bands, reduction in the energy separation between the Q(0,0) and Q(0,1) emission bands and shorter singlet and triplet state lifetimes. These effects are consistent with the porphyrin deformation resulting in changes in the porphyrin electronic structure and excited state conformational dynamics that alter the vibronic coupling between the excited states (S1 and T1) and the S0 ground state.

Disaggregation of Zinc Tetra(4-Carboxyphenoxy) Phthalocyaninate in Aqueous Solutions of Dodecyl-, Tetradecyl-, and Hexadecyltrimethylammonium Bromides at pH 6–9

The aggregation of zinc tetra(4-carboxyphenoxy) phthalocyaninate, ZnPc(COOH)4, in organic solvents and water at different pH values has been analyzed using electronic absorption and luminescence spectroscopies. It has been found that, in aqueous systems at pH 6–9, ZnPc(COOH)4 exists in an aggregated state, while it forms molecular solutions in dimethylformamide and dimethyl sulfoxide. The use of cationic surfactants (dodecyl-, tetradecyl-, and hexadecyltrimethylammonium bromides) causes the disaggregation of ZnPc(COOH)4 into individual molecules in aqueous solutions at pH ≥ 6. This opens up possibilities of applying ZnPc(COOH)4 as a preparation for photodynamic therapy in physiological solutions, because each molecule of this compound may participate in the generation of singlet molecular oxygen.

Parameters dependent synthesis of zinc stannate nanowires using CVD and its porphyrin dye loaded optical studies

Polycrystalline zinc stannate (Zn2SnO4) nanowires have been studied for its synthesis optimization using novel carbothermal catalytic method, wherein binary oxide precursors were used under inert atmosphere at variable CVD synthesis parameters. X-ray diffraction, FESEM, EDS, HRTEM, Raman and CL measurements are used to understand the typical behaviour of ternary metal oxide nanowires i.e. Zn2SnO4 growth. The optimization of Zn2SnO4 nanowires has been discussed via synthesis parameters followed with reaction equations corresponding to its optical and room temperature electrical properties. Further, its visible range sensitization has been demonstrated for suitable sample using zinc tetra phenyl porphyrin (ZnTPP) dye via dye adsorption method. Corresponding optical and IPCE studies of photo-electrodes shows broadened visible range absorption in 300–600 nm range and conversion efficiency of 28% (at ∼447 nm) for the nanowires having indirect band gap of ∼3.4 eV. This study opens up the potential application in photovoltaic, sensors and photo catalytic devices.

Uniform zinc thioporphyrazine nanosphere by self-assembly and the photocatalytic performance

A novel strategy for the synthesis of zinc thioporphyrazine nanospheres is presented. The uniform spheres were fabricated through a polymerization reaction without using any template or emulsifier, which result from the covalent links between zinc tetra(2,3-bis(pentenylthio)porphyrazine (ZnPz) possessing eight long flexible chains in periphery and each with one terminal olefin group. A possible mechanism to explain the self-assembly of ZnPz nanospheres was also illuminated through monitoring nanosphere formation by means of transmission electron microscopy (TEM). More importantly, ZnPz nanospheres can effectively activate dioxygen in aqueous media under simulated sunlight irradiation, and showed significantly improved photocatalytic activity for the degradation of Rhodamine B (RhB) as compared to monomeric ZnPz. Furthermore, the reactive oxygen species derived from ZnPz nanospheres under light irradiation were determined by electron paramagnetic resonance (EPR) technology, indicating that singlet oxygen ([Formula: see text]O[Formula: see text] and hydroxyl radical (•OH) are the major reactive oxygen species. The facile synthetic methodology and the enhanced photocatalytic performance of the ZnPz nanospheres endow this novel material with the potential of being an efficient biomimetic photocatalyst for wastewater treatment.

Reduced Graphene Oxide ‐ Zinc Phthalocyanine Composites as Fascinating Material for Optoelectronic and Photocatalytic Applications

AbstractReduced graphene oxide‐ zinc tetra tert‐butyl phthalocyanine (RGO‐ZnTTBPc) hybrid material has been synthesized through the reduction of graphene oxide (GO) in presence of ZnTTBPc. As‐prepared RGO‐ZnTTBPc thin film photodetector exhibited stable and reproducible photocurrent responses with a responsivity of 2 A/W under simulated solar light.A detailed study on electrical transport mechanism reveals the occurrence of phonon assisted quantum tunneling of charge carriers among the defect states present in RGO ‐ ZnTTBPc system. The relaxation dynamics of charge carriers in the composite is modulated by a temperature independent universal function. Furthermore, the resulting hybrid material showed an enhanced photocatalytic activity with 3.5 times higher reduction rate constant over controlled ZnTTBPc towards the reduction of 4‐nitrophenol under solar light irradiation. Superior photoresponse property and photocatalytic reduction was attributed to the synergistic effect between favorable matching of the lowest unoccupied molecular orbital (LUMO) level of ZnTTBPc to the work function of conductive RGO. The present work is especially important in the field of RGO‐based next‐generation photocatalysts and light energy harvesting applications.

Rationally encapsulated gold nanorods improving both linear and nonlinear photoacoustic imaging contrast in vivo.

Photoacoustic tomography has emerged as a promising non-invasive imaging technique that integrates the merits of high optical contrast with high ultrasound resolution in deep scattering medium. Unfortunately, the blood background in vivo seriously impedes the quality of imaging due to its comparable optical absorption with contrast agents, especially in conventional linear photoacoustic imaging modality. In this study, we demonstrated that two hybrids consisting of gold nanorods (Au NRs) and zinc tetra(4-pyridyl)porphyrin (ZnTPP) exhibited a synergetic effect in improving optical absorption, conversion efficiency from light to heat, and thermoelastic expansion, leading to a notable enhancement in both linear (four times greater) and nonlinear (more than six times) photoacoustic signals as compared with conventional Au NRs. Subsequently, we carefully investigated the interesting factors that may influence photoacoustic signal amplification, suggesting that the coating of ZnTPP on Au NRs could result in the reduction of gold interfacial thermal conductance with a solvent, so that the heat is more confined within the nanoparticle clusters for a significant enhancement of local temperature. Hence, both the linear and nonlinear photoacoustic signals are enhanced on account of better thermal confinement. The present work not only shows that ZnTPP coated Au NRs could serve as excellent photoacoustic nanoamplifiers, but also brings a perspective for photoacoustic image-guided therapy.

Reduced Graphene Oxide Non‐covalent Functionalized with Zinc Tetra Phenyl Porphyrin Nanocomposite for Electrochemical Detection of Dopamine in Human Serum and Rat Brain Samples

AbstractWe described the use of a nanocomposite consisting of reduced graphene oxide and zinc tetraphenylporphyrin (RGO/Zn‐TPP) for electrochemical sensing of dopamine (DA). The surface of RGO was homogeneously functionalized with Zn‐TPP via non‐covalent π‐π interaction. The nanocomposite was characterized by scanning electron microscopy, UV‐Vis spectrometry, nuclear magnetic resonance spectroscopy and electrochemical impedance spectroscopy. The electroanalysis behavior of the nanocomposite was studied by cyclic voltammetry and amperometry. The excellent electrocatalytic activity is found for oxidation of DA, best at working voltage of 0.214 V (vs. Ag/AgCl) and linear response range of 0.04–238.8 μM. The sensitivity and detection limit were of 0.665 μA µM−1 cm−2and 3 nM, respectrively. The electrode is well reproducible, stable, and represents a viable platform for the analysis of DA in DA injection, human serum and rat brain sample.

Synthesis and characterizations of a paddlewheel-type dirhodium-based photoactive porous metal-organic framework

A paddlewheel-type dirhodium-based, photoactive, porous metal-organic framework, [Rh2(ZnTCPP)(H2O)7.5] ([1]; ZnTCPP=zinc tetra(4-carboxyphenyl)porphyrin), was prepared and characterized via synchrotron X-ray analyses (X-ray powder diffraction, extended X-ray absorption fine structure, and X-ray absorption near-edge structure), elemental analysis, infrared spectroscopy, and N2 gas adsorption isotherm analysis. Spectroscopic study revealed a drastic decrease in the emission intensity of [1] compared with [ZnTCPP], although features present in the absorption spectra of the two complexes were almost the same. This indicated that [1] underwent the photo-induced intramolecular charge transfer and/or energy transfer from the ZnTCPP moiety to dirhodium moiety.

MCD spectroscopy and TD-DFT calculations of magnesium tetra-(15-crown-5-oxanthreno)-phthalocyanine

An analysis of the MCD spectroscopy and TD-DFT calculations of magnesium tetra-(15-crown-5-oxanthreno)-phthalocyanine is reported. This study provides a reassessment of an earlier study on the nature of the bands in UV-visible absorption spectra of magnesium and zinc tetra-(15-crown-5-oxanthreno)-phthalocyanine that was based on an analysis of TD-DFT calculations for a series of model complexes with the B3LYP functional. A detailed analysis of MCD spectral data and TD-DFT calculations with the CAM-B3LYP functional for the complete Mg(II) complex provides an additional insight into the optical properties and electronic structures of tetra-(15-crown-5-oxanthreno)-phthalocyanines. Thus, the bands in the Q-band region are reassigned as being due exclusively to the Q transition of Gouterman’s 4-orbital model, since intense pseudo-[Formula: see text] terms are observed in the MCD spectrum in a spectral region that had previously been assigned as charge transfer bands.

Bromination of β-positions of tetra(4-bromphenyl)porphyrin and its complex with Zn(II)

The reaction of 5,10,15,20-tetra(4-bromophenyl)porphyrin with N-bromosuccinimide in a mixture of chloroform with dimethylformamide afforded 2-bromo-5,10,15,20-tetra(4-bromophenyl)porphyrin. In similar conditions the bromination of Zn(II) 5,10,15,20-tetra(4-bromophenyl)porphyrinate led to Zn(II) 2,3,12,13-tetrabromo-5,10,15,20-tetra(4-bromophenyl)porphyrinate. By the bromination of β-tetrabromosubstituted zinc tetra(4-bromophenyl)porphyrinate with N-bromosuccinimide in a mixture chloroform–dimethylformamide Zn(II) 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetra(4-bromophenyl)porphyrinate was obtained. The synthesized compounds were characterized by electron absorption, 1Н NMR and mass spectra.