Showing papers on "Porphyrin published in 2020"

COVID-19: Attacks the 1-Beta Chain of Hemoglobin and Captures the Porphyrin to Inhibit Human Heme Metabolism

Abstract: The novel coronavirus pneumonia (COVID-19) is an infectious acute respiratory infection caused by the novel coronavirus The virus is a positive-strand RNA virus with high homology to bat coronavirus In this study, conserved domain analysis, homology modeling, and molecular docking were used to compare the biological roles of certain proteins of the novel coronavirus The results showed the ORF8 and surface glycoprotein could bind to the porphyrin, respectively At the same time, orf1ab, ORF10, and ORF3a proteins could coordinate attack the heme on the 1-beta chain of hemoglobin to dissociate the iron to form the porphyrin The attack will cause less and less hemoglobin that can carry oxygen and carbon dioxide The lung cells have extremely intense poisoning and inflammatory due to the inability to exchange carbon dioxide and oxygen frequently, which eventually results in ground-glass-like lung images The mechanism also interfered with the normal heme anabolic pathway of the human body, is expected to result in human disease According to the validation analysis of these finds, chloroquine could prevent orf1ab, ORF3a, and ORF10 to attack the heme to form the porphyrin, and inhibit the binding of ORF8 and surface glycoproteins to porphyrins to a certain extent, effectively relieve the symptoms of respiratory distress Favipiravir could inhibit the envelope protein and ORF7a protein bind to porphyrin, prevent the virus from entering host cells, and catching free porphyrins Because the novel coronavirus is dependent on porphyrins, it may originate from an ancient virus Therefore, this research is of high value to contemporary biological experiments, disease prevention, and clinical treatment br

2D sp2 Carbon-Conjugated Porphyrin Covalent Organic Framework for Cooperative Photocatalysis with TEMPO.

Abstract: 2D covalent organic frameworks (COFs) are receiving ongoing attention in semiconductor photocatalysis. Herein, we present a photocatalytic selective chemical transformation by combining sp2 carbon-conjugated porphyrin-based covalent organic framework (Por-sp2 c-COF) photocatalysis with TEMPO catalysis illuminated by 623 nm red light-emitting diodes (LEDs). Highly selective conversion of amines into imines was swiftly afforded in minutes. Specifically, the π-conjugation of porphyrin linker leads to extensive absorption of red light; the sp2 -C=C- double bonds linkage ensures the stability of Por-sp2 c-COF under high concentrations of amine. Most importantly, we found that crystalline framework of Por-sp2 c-COF is pivotal for cooperative photocatalysis with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO). This work foreshadows that the outstanding hallmarks of COFs, particularly crystallinity, could be exploited to address energy and environmental challenges by cooperative photocatalysis.

Low-Bandgap Porphyrins for Highly Efficient Organic Solar Cells: Materials, Morphology, and Applications

Abstract: With developments in materials, thin-film processing, fine-tuning of morphology, and optimization of device fabrication, the performance of organic solar cells (OSCs) has improved markedly in recent years Designing low-bandgap materials has been a focus in order to maximize solar energy conversion However, there are only a few successful low-bandgap donor materials developed with near-infrared (NIR) absorption that are well matched to the existing efficient acceptors Porphyrin has shown great potential as a useful building block for constructing low-bandgap donor materials due to its large conjugated plane and strong absorption Porphyrin-based donor materials have been shown to contribute to many record-high device efficiencies in small molecule, tandem, ternary, flexible, and OSC/perovskite hybrid solar cells Specifically, non-fullerene small-molecule solar cells have recently shown a high power conversion efficiency of 12% using low-bandgap porphyrin All these have validated the great potential of porphyrin derivatives as effective donor materials and made DPPEZnP-TRs a family of best low-bandgap donor materials in the OSC field so far Here, recent progress in the rational design, morphology, dynamics, and multi-functional applications starting from 2015 will be highlighted to deepen understanding of the structure-property relationship Finally, some future directions of porphyrin-based OSCs are presented

Elucidating heterogeneous photocatalytic superiority of microporous porphyrin organic cage.

Abstract: The investigation on the catalytic properties of porous organic cages is still in an initial stage. Herein, the reaction of cyclohexanediamine with 5,15-di[3’,5’-diformyl(1,1’-biphenyl)]porphyrin affords a porphyrin tubular organic cage, PTC-1(2H). Transient absorption spectroscopy in solution reveals much prolonged triplet lifetime of PTC-1(2H) relative to monomer reference, illustrating the unique photophysical behavior of cagelike photosensitizer. The long triplet lifetime ensures high-efficiency singlet oxygen evolution according to homogeneous photo-bleach experiment, electron spin-resonance spectroscopy, and aerobic photo-oxidation of benzylamine. Furthermore, microporous supramolecular framework of PTC-1(2H) is able to promote the heterogeneous photo-oxidation of various primary amines with conversion efficiency above 99% under visible light irradiation. These results indicate the great application potentials of porous organic cages in heterogeneous phase. The investigation on the catalytic properties of porous organic cages is still in an initial stage. Herein, the heterogeneous photocatalytic superiority of microporous porphyrin organic cage has been clearly elucidated due to unique cage-induced long triplet lifetime and porous structure.

Photocatalytic CO2 Reduction Mediated by Electron Transfer via the Excited Triplet State of Zn(II) Porphyrin

Abstract: A porphyrin/rhenium complex dyad, ZnP-phen=Re, in which the 2-position of the 1,10-phenanthroline (phen) of fac-Re(phen)(CO)3Br is directly connected with the meso-position of zinc(II) porphyrin, s...

Catalytic Porphyrin Framework Compounds

Abstract: Porphyrins are frequently observed in nature and play a vital role in many biological functions, including light-harvesting, oxygen transport, and catalytic transformations. The rigid, robust, and multifunctional features of porphyrins enable the construction of framework compounds such as metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) for use in several important applications. This short review summarizes the types of porphyrin building blocks with varying connectivity, their assembly into framework compounds, and key structural factors governing porphyrin ligand design. Furthermore, we highlight emerging catalytic applications of these porphyrin framework compounds as Lewis acid catalysts, oxidation catalysts, photocatalysts, and electrocatalysts. Together, this review supplies a timely update on porphyrin ligand design and framework compound synthesis and guides the future development of porphyrin framework compounds with diverse functionalities for efficient catalysis.

Improved Photoreduction of CO2 with Water by Tuning the Valence Band of Covalent Organic Frameworks.

Abstract: Porous covalent organic frameworks (COFs), as an emerging material, have the characteristics of high stability, large series of components, easy synthesis, modification, and adjustable amplitude. They have the potential to become good catalysts. Bromine, as a halogen, has attracted intensive interest for the modification of photocatalysts for photocatalytic reactions. It is feasible to enhance the activity and selectivity of the material by facile functionalization of the reticular parent structure's electron-withdrawing groups. In addition, the conjugation effect of bromine, further delocalizing the electrons of the COF, is beneficial to the progress of many photocatalytic reactions. Reports on the modification of COFs by bromine functional groups to improve the catalytic performance have not been found so far. Here, TAPP [5,10,15,20-tetrakis(4-aminophenyl)porphyrin] and 2,5-dibromo-1,4-benzenedialdehyde instead of terephthalaldehyde were chosen to synthesize a porphyrin-based COF (TAPBB-COF) by the solvothermal method. As expected, the valence band (VB) of TAPBB-COF is thus adjusted to a more suitable position. Additionally, the CO production when using TAPBB-COF under full-wavelength light for 12 h was 295.2 μmol g-1 , which was three times that of COF-366, and the new material has good recycling stability and selectivity (95.6 %). Theoretical calculations indicate that the nitrogen of the porphyrin ring and the Schiff base, and the bromine in TAPBB-COF contribute greatly to the activation of H2 O and the conversion of CO2 in the photoreaction.

A novel copper-bridged graphitic carbon nitride/porphyrin nanocomposite with dramatically enhanced photocatalytic hydrogen generation

Abstract: With Cu as interfacial linkers, meso-tetra (4-carboxyphenyl) porphyrin (TCPP) as visible light absorption antennas, and graphitic carbon nitride (g-C3N4) as a substance, a novel g-C3N4/porphyrin nanocomposite (g-C3N4-Cu-TCPP) with enhanced light absorption and efficient electron transfer was facilely assembled. The morphology, composition, and structure of the nanocomposite were characterized by TEM, XPS, XRD and infrared spectroscopy. The results showed that the introduction of Cu in the interface of g-C3N4 and TCPP can smartly regulate the morphology and structure of the g-C3N4-TCPP. More importantly, the interaction between TCPP and g-C3N4 was greatly strengthened. Subsequently, the electron transfer between g-C3N4 and TCPP was effectively promoted, and the activity of photocatalytic hydrogen production was dramatically improved without loading other cocatalysts, which showed the vital role of Cu implanted in the g-C3N4/TCPP.

Amplified Electrochemical Hydrogen Peroxide Sensing Based on Cu-porphyrin Metal Organic Framework Nanofilm and G-quadruplex-hemin DNAzyme

Abstract: A novel electrochemical hydrogen peroxide (H2O2) sensor based on Cu-porphyrin(Cu-TCPP)/G-quadruplex-hemin nanocomposite was constructed by assembling two-dimensional Cu-TCPP metal organic framework...

A Planar, Conjugated N 4 -Macrocyclic Cobalt Complex for Heterogeneous Electrocatalytic CO 2 Reduction with High Activity

Abstract: Metal complexes have been widely investigated as promising electrocatalysts for CO2 reduction Most of the current research efforts focus mainly on ligands based on pyrrole subunits, and the reported activities are still far from satisfactory A novel planar and conjugated N4 -macrocyclic cobalt complex (Co(II)CPY) derived from phenanthroline subunits is prepared herein, and it delivers high activity for heterogeneous CO2 electrocatalysis to CO in aqueous media, and outperforms most of the metal complexes reported so far At a molar loading of 593×10-8 mol cm-2 , it exhibits a Faradaic efficiency of 96 % and a turnover frequency of 959 s-1 towards CO at -070 V vs RHE The unraveling of electronic structural features suggests that a synergistic effect between the ligand and cobalt in Co(II)CPY plays a critical role in boosting its activity As a result, the free energy difference for the formation of *COOH is lower than that with cobalt porphyrin, thus leading to enhanced CO production

Bacterial Detection and Elimination Using a Dual-Functional Porphyrin-Based Porous Organic Polymer with Peroxidase-Like and High Near-Infrared-Light-Enhanced Antibacterial Activity

Abstract: The efficient fabrication of multifunctional nanoplatforms for bacterial detection and elimination is of great importance in nanobiotechnology. A new porphyrin-based porous organic polymer, FePPOPB...

Semiconductive Porphyrin-Based Covalent Organic Frameworks for Sensitive Near-Infrared Detection.

Abstract: A porphyrin-based two-dimensional (2D) covalent organic framework (COF) was developed by a C4 + C4 topological diagram. It was constructed by the condensation of zinc 5,10,15,20-tetra(4-aminophenyl...

Significantly improved electrocatalytic oxygen reduction by an asymmetrical Pacman dinuclear cobalt( ii ) porphyrin–porphyrin dyad

Abstract: Pacman dinuclear CoII triphenylporphyrin-tri(pentafluorophenyl)porphyrin 1 and dinuclear CoII bis-tri(pentafluorophenyl)porphyrin 2, anchored at the two meso-positions of a benzene linker, are synthesized and examined as electrocatalysts for the oxygen reduction reaction (ORR). Both dinuclear Co bisporphyrins are more efficient and selective than corresponding mononuclear CoII tetra(pentafluorophenyl)porphyrin 3 and CoII tetraphenylporphyrin 4 for the four-electron electrocatalytic reduction of O2 to water. Significantly, although the ORR selectivities of the two dinuclear Co bisporphyrins are similar to each other, 1 outperforms 2, in terms of larger catalytic ORR currents and lower overpotentials. Electrochemical studies showed different redox behaviors of the two Co sites of 1: the CoIII/CoII reduction of the Co-TPP (TPP = triphenylporphyrin) site is well-behind that of the Co-TPFP (TPFP = tri(pentafluorophenyl)porphyrin) site by 440 mV. This difference indicated their different roles in the ORR: CoII-TPFP is likely the O2 binding and reduction site, while CoIII-TPP, which is generated by the oxidation of CoII-TPP on electrodes, may function as a Lewis acid to assist the O2 binding and activation. The positively charged CoIII-TPP will have through-space charge interactions with the negatively charged O2-adduct unit, which will reduce the activation energy barrier for the ORR. This effect of Co-TPP closely resembles that of the CuB site of metalloenzyme cytochrome c oxidase (CcO), which catalyzes the biological reduction of O2. This work represents a rare example of asymmetrical dinuclear metal catalysts, which can catalyze the 4e reduction of O2 with high selectivity and significantly improved activity.

Copper Porphyrin as a Stable Cathode for High Performance Rechargeable Potassium Organic Batteries

Abstract: Rechargeable potassium-ion batteries (KIBs) are promising alternatives to lithium-ion batteries for large-scale electrochemical energy-storage applications because of the abundance and low cost of potassium. However, the development of KIBs is hampered by the lack of stable and high-capacity cathode materials. Herein, a functionalized porphyrin complex, [5,15-bis(ethynyl)-10,20-diphenylporphinato]copper(II) (CuDEPP), was proposed as a new cathode for rechargeable potassium batteries. Spectroscopy and molecular simulation studies were used to show that both PF6- and K+ interact with the porphyrin macrocycle to allow a four-electron transfer. In addition, the electrochemical polymerization of the ethynyl functional groups in CuDEPP resulted in the self-stabilization of the cathode, which was highly stable during cycling. This unique charge storage mechanism enabled CuDEPP to provide a capacity of 181 mAh g-1 with an average potential of 2.8 V (vs. K+ /K). These findings could open a pathway towards the design of new stable organic electrodes for KIBs.

Recent Advances in Porphyrin-Based Materials for Metal Ions Detection

Abstract: Porphyrins have planar and conjugated structures, good optical properties, and other special functional properties. Owing to these excellent properties, in recent years, porphyrins and their analogues have emerged as a multifunctional platform for chemical sensors. The rich chemistry of these molecules offers many possibilities for metal ions detection. This review mainly discusses two types of molecular porphyrin and porphyrin composite sensors for metal ions detection, because porphyrins can be functionalized to improve their functional properties, which can introduce more chemical and functional sites. According to the different application materials, the section of porphyrin composite sensors is divided into five sub-categories: (1) porphyrin film, (2) porphyrin metal complex, (3) metal-organic frameworks, (4) graphene materials, and (5) other materials, respectively.

A promising anticancer drug: a photosensitizer based on the porphyrin skeleton

Abstract: Photodynamic therapy (PDT) is a minimally invasive combination of treatments that treat tumors and other diseases by using photosensitizers, light and oxygen to produce cytotoxic reactive oxygen species (ROS) inducing tumor cell apoptosis. Photosensitizers are the key part of PDT for clinical application and experimental research, and most of them are porphyrin compounds at present. Due to their unique affinity for tumor tissues, porphyrins are not only excellent photosensitizers, but also good carriers to transport other active drugs into tumor tissues, which can exert synergistic anticancer effects of PDT and chemotherapy. This article reviews the clinical development of porphyrin photosensitizers and the research status of porphyrin containing bioactive groups. Finally, future perspectives and the current challenges of photosensitizers based on the porphyrin skeleton are discussed.

Encapsulation of Single Iron Sites in a Metal-Porphyrin Framework for High-Performance Photocatalytic CO2 Reduction.

Abstract: Efficient CO2 reduction with earth-abundant photocatalysts is a highly attractive but very challenging process for chemists. Herein, we synthesized an indium-porphyrin framework, In(H2TCPP)(1-n)[Fe(TCPP)(H2O)](1-n)[DEA](1-n) (In-FenTCPP-MOF; H2TCPP = tetrakis(4-benzoic acid)porphyrine; DEA = diethylamine), with a porphyrin ring supporting the single-site iron for the high-performance visible-light-driven conversion of CO2 to CO. A high CO yield of 3469 μmol g-1 can be achieved by a 24 h photocatalytic reaction with a high CO selectivity (ca. 99.5%). This activity was much higher than that of its cobalt analogues or the Fe-free indium-based metal-organic framework (MOF). Systematic experimental and theoretical studies indicate that the porphyrin-supported iron centers in the MOF matrix serve as efficient active sites, which can accept electrons from the photoexcited MOFs in order to mediate CO2 reduction.

Efficient cosensitization of new organic dyes containing bipyridine anchors with porphyrins for dye-sensitized solar cells

Abstract: One of the core problems facing DSSCs is that they only partially absorb the solar spectrum, and a feasible solution is to co-sensitize two or more dyes with different absorption spectra to achieve panchromatic absorption. Herein, two organic dyes S3 and S4 containing bipyridine anchoring groups were prepared and used as co-sensitizers to assemble solar cells with porphyrin dye JA3. In the structural design of S3 and S4, we use diphenylthiazide and carbazole with a long carbon chain as electron donors and dipyridine with better planarity as an electron acceptor, and this is conducive to increasing the intramolecular charge transfer performance of dyes, inhibiting dye aggregation and increasing the amount of dye loading. Optical performance analysis shows that the light-harvesting ability of the device has been significantly improved after the co-sensitization of the two organic molecules with porphyrin dye JA3. At the same time, the charge recombination of porphyrin dyes has been significantly reduced because the appropriate molecular volume structures of S3 and S4 can fill the adsorption gap between porphyrin dyes. The DSSC based on JA3 shows a PCE of 6.23%, with a Voc of 801 mV, a Jsc of 12.23 mA cm−2, and a FF of 63.55%. After co-sensitization, the overall performance of the device has been significantly improved; both short-circuit current and open-circuit voltage have been greatly enhanced. The DSSC based on JA3 + S3 shows a high PCE of 8.20%, with a Voc of 821 mV, a Jsc of 15.46 mA cm−2, and a FF of 64.55%. The co-sensitizer not only successfully compensates for the absorption defects of porphyrin dyes in the range of 500–600 nm and improves the light response current, but also fills the adsorption gap between the main dyes, and effectively suppresses the charge recombination behavior, thus improving the open-circuit voltage of the device.

An anticancer gold(III)-activated porphyrin scaffold that covalently modifies protein cysteine thiols

Abstract: Cysteine thiols of many cancer-associated proteins are attractive targets of anticancer agents. Herein, we unequivocally demonstrate a distinct thiol-targeting property of gold(III) mesoporphyrin IX dimethyl ester (AuMesoIX) and its anticancer activities. While the binding of cysteine thiols with metal complexes usually occurs via M–S bond formation, AuMesoIX is unique in that the meso-carbon atom of the porphyrin ring is activated by the gold(III) ion to undergo nucleophilic aromatic substitution with thiols. AuMesoIX was shown to modify reactive cysteine residues and inhibit the activities of anticancer protein targets including thioredoxin, peroxiredoxin, and deubiquitinases. Treatment of cancer cells with AuMesoIX resulted in the formation of gold-bound sulfur-rich protein aggregates, oxidative stress-mediated cytotoxicity, and accumulation of ubiquitinated proteins. Importantly, AuMesoIX exhibited effective antitumor activity in mice. Our study has uncovered a gold(III)-induced ligand scaffold reactivity for thiol targeting that can be exploited for anticancer applications.

Iron porphyrin catalysed light driven C–H bond amination and alkene aziridination with organic azides

Abstract: Visible light driven nitrene transfer and insertion reactions of organic azides are an attractive strategy for the design of C–N bond formation reactions under mild reaction conditions, the challenge being lack of selectivity as a free nitrene reactive intermediate is usually involved. Herein is described an iron(III) porphyrin catalysed sp3 C–H amination and alkene aziridination with selectivity by using organic azides as the nitrogen source under blue LED light (469 nm) irradiation. The photochemical reactions display chemo- and regio-selectivity and are effective for the late-stage functionalization of natural and bioactive compounds with complexity. Mechanistic studies revealed that iron porphyrin plays a dual role as a photosensitizer and as a catalyst giving rise to a reactive iron–nitrene intermediate for subsequent C–N bond formation.

Recent progress in porphyrin- and phthalocyanine-containing perovskite solar cells

Abstract: In this review, we summarize the application of porphyrins and phthalocyanines in perovskite solar cells to date. Since the first porphyrin- and phthalocyanine-based perovskite solar cells were reported in 2009, their power conversion efficiency has dramatically increased from 3.9% to over 20%. Porphyrins and phthalocyanines have mostly been used as the charge selective layers in these cells. In some cases, they have been used inside the perovskite photoactive layer to form two-dimensional perovskite structures. In other cases, they were used at the interface to engineer the surface energy level. This review gives a chronological introduction to the application of porphyrins and phthalocyanines for perovskite solar cells depending on their role. This review article also provides the history of porphyrin and phthalocyanine derivative development from the perspective of perovskite solar cell applications.