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Carbon monoxide poisoning is one of the most common forms of poisoning in the world. Although the primary mode of treatment, oxygen therapy, is highly effective in many cases, there are instances in which it is inadequate or inappropriate. Whereas oxygen therapy relies on high levels of a low-affinity ligand (O2) to displace a high-affinity ligand (CO) from metalloproteins, an antidote strategy relies on introducing a molecule with a higher affinity for CO than native proteins (Kantidote,CO > Kprotein,CO). Based on the fundamental chemistry of CO, such an antidote is most likely required to be an inorganic compound featuring an electron-rich transition metal. A review is provided of the protein-, supramolecular complex-, and small molecule-based CO poisoning antidote platforms that are currently under investigation.

ABSTRACT The structural, optoelectronic and charge transport properties of porphyrin and its analogues are investigated using the density functional theoretical methods. Most of the above molecules absorb in visible region with high light harvesting efficiency. The small energy gap between the frontier molecular orbitals (FMOs) suggests that porphyrin and its derivatives can be used in organic semiconductors. Electronic properties such as ionization potential, electron affinity, reorganization energy and the charge transfer integral are calculated to obtain their charge transport properties. It is revealed that porphyrin, porphyrazine and phthalocyanine act as hole transporters, whereas corrole and corrolazine act as electron transporters. [ABSTRACT FROM AUTHOR]

Ammonia (NH3) is an important raw material in the chemical industry, but the synthesis of NH3 by the traditional Haber‐Bosch process will increase the carbon footprint. Therefore, it is necessary to develop sustainable routes for NH3 production. New NH3 production schemes, including nitrogen reduction (N2RR), nitrite reduction (NO2RR), and nitrate reduction (NO3RR), have been proposed. Porphyrins and phthalocyanines are macrocyclic compounds with a central metal ion coordinated with nitrogen. The metal centers in these catalysts play a crucial role in binding and activating nitrogen, nitrite, and nitrate. Their unique structure allows for effective electron transfer and catalytic activation in NH3 synthesis. Recently, metal porphyrin and phthalocyanine based catalysts have been demonstrated to be efficient in catalyzing N2RR, NO2RR, and NO3RR. Unfortunately, there is no review focusing on such macrocyclic catalysts for the electrocatalytic synthesis of NH3. In this review, we discuss the electrocatalytic reduction performances and summarize the key factors and reaction mechanisms that affect the catalytic performance of metal porphyrin and phthalocyanine based catalyst systems. This review helps to design more effective new electrocatalysts for NH3 synthesis. [ABSTRACT FROM AUTHOR]

This study employed a computational approach, particularly Density Functional Theory at B3LYP−D3/6‐31+G(d) level to design two new classes of three‐dimensional (3D) Lantern Organic Frameworks (LOFs) materials based on trisilasumanene and porphyrin core building units. Particularly, we detail strategies for transitioning from 1D‐LOF nanowires to extended 3D structures: first by connecting planar‐molecule base units of trisilasumanene or porphyrin using benzene‐based linkers, and then connecting silicon anchoring atoms on the bases with other bases that are vertically stacked by sp3‐hydrocarbon chains. The 3D‐LOF structures are designed to have different pore sizes through the use of various bases, bridges, and linkers. Comparisons of electronic properties of these 3D structures lead to one designing rule. That is, the gap between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the 3D materials depends only on its base and is nearly independent of the stack size or the length of the sp3‐hydrocarbon bridges. Additionally, connecting base units with linkers also extends π‐electron conjugation system leading to a reduction in HOMO‐LUMO gap. For instance, linking two trisilasumanene molecules significantly narrows HOMO‐LUMO gap by 1.75 eV while stacking these bases vertically and connecting them by linear pentane‐based bridges yield insignificant change to the gap. [ABSTRACT FROM AUTHOR]

Photodynamic therapy and ferroptosis induction have risen as vanguard oncological interventions, distinguished by their precision and ability to target vulnerabilities in cancer cells. Photodynamic therapy's non-invasive profile and selective cytotoxicity complement ferroptosis' unique mode of action, which exploits iron-dependent lipid peroxidation, offering a pathway to overcome chemoresistance with lower systemic impact. The synergism between photodynamic therapy and ferroptosis is underscored by the depletion of glutathione and glutathione peroxidase four inhibitions by photodynamic therapy-induced reactive oxygen species, amplifying lipid peroxidation and enhancing ferroptotic cell death. This synergy presents an opportunity to refine cancer treatment by modulating redox homeostasis. Porphyrin-based nanoscale metal-organic frameworks have unique hybrid structures and exceptional properties. These frameworks can serve as a platform for integrating photodynamic therapy and ferroptosis through carefully designed structures and functions. These nanostructures can be engineered to deliver multiple therapeutic modalities simultaneously, marking a pivotal advance in multimodal cancer therapy. This review synthesizes recent progress in porphyrin-modified nanoscale metal-organic frameworks for combined photodynamic therapy and ferroptosis, delineating the mechanisms that underlie their synergistic effects in a multimodal context. It underscores the potential of porphyrin-based nanoscale metal-organic frameworks as advanced nanocarriers in oncology, propelling the field toward more efficacious and tailored cancer treatments. [ABSTRACT FROM AUTHOR]

Non‐covalent interactions offer an alternative way for developing stimulus‐responsive materials such as sensors, machines, and drug‐delivery systems. We recently reported that a urethane‐equipped tetrakis(porphyrin) forms one‐handed helical supramolecular polymers in solution in response to chirality of chiral solvents. Conformational changes in helical sense were detected using circular dichroism (CD) spectroscopy, which showed that the tetrakis(porphyrin) can possibly be used as a sensor for determining the enantiomeric excess of a chiral analyte. Hence, we studied the scope and limitations of the chiral‐induction behavior of tetrakis(porphyrin) to deepen the understanding of tetrakis(porphyrin)‐based chiral sensing systems. Herein, we report the chiral‐induction behavior of tetrakis(porphyrin) in various chiral solvents, which was found to be CD‐active in many chiral solvents. Notably, the tetrakis(porphyrin) was CD active in a cryptochiral molecular solvent, which is exciting because the chiralities of acyclic saturated hydrocarbons are hard to sense. Consequently, this study highlights the potential advantages of supramolecular chiral sensors capable of targeting a wide range of analytes, including molecules that are absorption‐silent in the UV/vis region, ones devoid of anchoring functional groups, and acyclic, saturated hydrocarbons. [ABSTRACT FROM AUTHOR]

A reversible associated copolymer capable of healing at room temperature was constructed using acrylic acid (AA) and hemin as anionic monomers, and methacryloyloxyethyl trimethylammonium chloride (DMC) as the cationic monomer. Through optimization of the synthesis conditions, characterization by 1HNMR, infrared spectroscopy, ultraviolet-visible spectroscopy, Thermogravimetric analysis, differential scanning calorimetry, and construction of reasonable models for dynamic simulation, the following conclusions were obtained: The introduction of Hemin could convert light energy into heat energy, accelerating the healing of damaged areas; the predicted glass transition temperature value matched well with the experimental value, demonstrating the reliability of the constructed polymer model; the cohesive energy density (CED), dominated by electrostatic interactions, was identified as the key factor in the self-healing mechanism; the study also visually captured the microscopic process of self-healing within the polymer, providing a detailed understanding of the molecular rearrangements that facilitate this process. This work offers valuable insights into the design of reversible associated polymers, contributing to the broader goal of developing functional polymer materials aligned with circular economy principles. [ABSTRACT FROM AUTHOR]

Porphyrin‐based nanohoops, nanorings, and cages with fully π‐conjugated structures are highly sought after, but their synthesis remains challenging. Herein, we report the template‐free synthesis of a highly strained, bithiophene‐bridged porphyrin cyclophane (1) from a porphyrin quinone via a stereoselective nucleophilic addition followed by intermolecular Yamamoto coupling strategy. X‐ray crystallographic analyses of 1 and its dication 12+ reveal significantly distorted cyclophane‐like geometries, with calculated strain energies of 51.2 and 80.7 kcal/mol, respectively. While the neutral compound 1 exhibits localized aromaticity, the dication 12+ is globally aromatic, with the porphyrin unit displaying weak antiaromaticity. Additionally, the dication 12+ undergoes nucleophilic addition with chloride, relieving strain. This work presents a novel synthetic strategy for highly strained, fully π‐conjugated systems with intriguing electronic properties and chemical reactivity. [ABSTRACT FROM AUTHOR]

Tetrakisporphyrin monomers with amino acid side chains at each end form intramolecular antiparallel hydrogen‐bonds to adopt chirally twisted pseudo‐macrocyclic structures that result in right‐handed and left‐handed (P)‐ and (M)‐conformations. The pseudo‐macrocyclic tetrakisporphyrin monomers self‐assembled to form supramolecular helical pseudo‐polycatenane polymers via head‐to‐head complementary dimerization of the bisporphyrin cleft units in an isodesmic manner. The formation of one‐handed supramolecular helical pseudo‐polycatenane polymers was confirmed by circular dichroism (CD) spectroscopy. The methyl and iso‐propyl groups at the stereogenic center greatly enhanced the induced circular dichroism in the Soret bands of the supramolecular helical pseudo‐polycatenane polymers. The induced CDs were reduced upon the introduction of large iso‐butyl and tert‐butyl groups. Atomic force microscopy revealed well‐grown and long supramolecular helical pseudo‐polycatenane polymer chains with chain lengths in the range of 361 to 13.6 nm. The right‐handed helical chains were established by the self‐assembly of the right‐handed (P)‐conformation of the pseudo‐macrocyclic monomer. [ABSTRACT FROM AUTHOR]

Anthracene has served as an important building block of conjugated polymers with the connecting positions playing a crucial role for the electronic structures. Herein, anthracene units have been coupled through their 2,7‐carbons to develop an unprecedented, conjugated polymer, namely, poly(2,7‐anthrylene) featuring additional peri‐fused porphyrin edges. The synthesis starts from a 2,7‐dibromo‐9‐nickel(II) porphyrinyl‐anthracene as the pivotal precursor. Polymerization is achieved by an AA‐type Yamamoto coupling, followed by a polymer‐analogous oxidative cyclodehydrogenation to obtain a peri‐fusion between porphyrin and anthracene moieties. Although further cyclodehydrogenation between the repeating units cannot be achieved in solution, the thermal treatment of the precursor polymer derived from 2,7‐dibromo‐9‐porphyrinyl‐anthracene on a metal surface realizes the full cyclodehydrogenation. The difference between solution and on‐surface reactivity can be rationalized by the larger dihedral angle between repeat units in solution, which is reduced under the pronounced interaction with the metal surface. The peri‐fusion in the title polymer gives rise to a narrow electronic band gap optical absorptions extending far into the near‐infrared region. Oligomeric models are synthesized as well to support the analyses of the electronic and photophysical properties. [ABSTRACT FROM AUTHOR]

ABSTRACT A highly selective fluorescent sensor Por‐RBO for determination of Hg2+ was designed and synthesized with Rhodamine B and Tetraphenylporphyrin. The sensor can determine the Hg2+ of a solution within the pH 5.0–8.0, free from interference of other metal ions. When detected in buffer solution, the fluorescence was the strongest when five times the concentration of Hg2+ ion was added. Calculated by fluorescence titration method, the detection limit of sensor Por‐RBO for Hg2+ ion was as low as 0.12 μmol/L. The geometries of Por‐RBO and Por‐RBO‐Hg2+ were optimized at the B3LYP/6‐31G** level by density functional theory. The charge distribution, orbital interactions, and bonding characteristics were analyzed and compared in detail to discuss the recognition mechanism and structure–fluorescence property relationships. The results of cell fluorescence imaging and CCK‐8 experiments indicate that the sensor Por‐RBO exhibits lower cytotoxicity. Por‐RBO can be used for fluorescence distribution imaging of Hg2+ in living cells. [ABSTRACT FROM AUTHOR]

Developing activatable photodynamic agents is becoming a promising mode for realizing selective photodynamic therapy (PDT) in cancer treatment. However, till now only a few H2S‐activatable photodynamic agents have been involved in this field. Here, we fabricated H2S‐activatable nano‐assemblies (P@TPPCY) for the treatment of colon cancer containing high concentration H2S. The H2S‐activatable photosensitizer (TPPCY) was synthesized by covalent conjugation between tetraphenylporphyrin (TPP) and heptamethine cyanine (Cy7), and then TPPCY was encapsulated by an amphiphilic polymer DSPE‐mPEG to form P@TPPCY nano‐assemblies. We demonstrated that the photosensitizing effect of TPP was efficiently quenched by Cy7 with strong absorption in the NIR region via fluorescence resonance energy transfer (FRET) effect. Interestingly, the FRET effect between Cy7 and TPP was attenuated by the decrease of absorption of Cy7 in the NIR region after the Cy7 reacted with H2S, and then the photosensitizing effect of TPP in P@TPPCY was activated. Strikingly, the P@TPPCY showed efficient H2S‐activatable photodynamic therapy (PDT) in vitro against HCT116 cells (human colon carcinoma cell line), thus this work provides a new method for realizing accurate treatment of colon cancer in virtue of high H2S concentration microenvironment. [ABSTRACT FROM AUTHOR]

Achieving smart single‐phase materials with switchable thermal expansion is challenging, as most materials undergo volumetric thermal expansion upon heating. Here, it is reported that the porphyrin‐based metal‐organic frameworks (MOFs) can show switchable thermal expansion, ranging from negative to positive, by controlling the central metal ions. The pristine compound, along with those functionalized with Ni2+ or FePz2+ (Pz stands for pyrazine) show pronounced negative thermal expansion (NTE), while the FeCl2+ functionalized analogue shows moderate positive thermal expansion (PTE). Detailed molecular dynamic simulations shed light on that the NTE originates from the collective low‐frequency phonon modes, concerning the in‐plane/out‐of‐plane rotations and trampoline‐like vibrations of porphyrin groups. The introduction of FeCl2+ can disrupt the planarity of the porphyrin groups, stiffening the NTE related phonons, thus leading to the PTE. In contrast, the introduction of Ni2+ or FePz2+ groups can maintain the planar structure, thereby preserving the NTE. This study not only provides a molecular‐level understanding of thermal expansion but also opens a pathway for tailoring thermal expansion through post‐synthesis modification of molecular structures. [ABSTRACT FROM AUTHOR]

In this work, zinc oxide with different morphologies and textural properties were prepared and sensitized with metalloporphyrins (MPs) aiming to improve its solar energy harvesting capability for H2 production by water splitting under sunlight (a 300 W Xe/Hg lamp). An anionic iron(III)porphyrin and a cationic manganese(III)porphyrin were immobilized on different ZnO solids predominantly by electrostatic interactions. In general, the prepared MP‐free ZnO solid yielded modest catalytic results which had apparently no direct correlation with their textural properties or morphology. On the other hand, when these ZnO solids had iron or manganese porphyrin sensitizing them, their catalytic performances changed and a superior yield towards H2 production was observed in comparison to the pure ZnO solids, making evident the synergy achieved between these two components (ZnO and metalloporphyrins) for the prepared solids. It was also observed that the metalloporphyrins and the respective free‐base ligand suffered redox reactions when used as homogenous catalyst in this reaction, which could influence their performances as catalysts. The same was not observed in the solids containing immobilized MP, suggesting some protective effect of the ZnO solids on the MP complexes upon immobilization probably due to interaction of the complexes with the ZnO matrix. [ABSTRACT FROM AUTHOR]

Nickel 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 (O2•_) 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 O2•_. 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. [ABSTRACT FROM AUTHOR]

Sonodynamic therapy (SDT), as a promising non‐invasive therapeutic modality combining ultrasound (US) and sonosensitizers to produce cytotoxic reactive oxygen species (ROS) for treating deep‐seated tumors, has received increasing attention in recent years. Porphyrins are multifunctional organic materials, which can be excited both by light and US to produce ROS and possess various fascinating features, including controllable synthetic processes, excellent biodegradability, low cytotoxicity without light or US. Nevertheless, their poor water solubility, skin‐photosensitive toxicity, and insufficient target specificity hinder their clinical applications as sonosensitizer. Although the target specificity issue may be improved by using nanoparticle carriers, and the SDT efficacy can be enhanced by combining with other therapeutic modalities, such combination therapy makes it more confusing about the true mechanism of SDT. This review will focus on the following points: 1) Why are porphyrin‐based sonosensitizers considered the most promising sonosensitizer for clinical applications of SDT? 2) Recent progress in the development of multifunctional porphyrin‐based sonosensitizers. 3) What new insight has been gained on the mechanism of SDT in recent years? 4) The development trend of designing more efficient multifunctional porphyrin‐based sonosensitizers and existing challenges. Finally, future perspective of practical clinical applications of SDT based on multifunctional porphyrin‐based sonosensitizers will be discussed. [ABSTRACT FROM AUTHOR]

The present study synthesized a novel dendrimer with specific functional groups and use them as pharmaceutical carriers at the nanoscale. First, a glycodendrimer was synthesized and a porphyrin substance was selected as its core. Afterward, this substance was subsequently reacted with gallic acid and bromo valerate step-by-step and it was conjugated with acrylonitrile functionalized with Tris (hydroxymethyl) aminomethane. Eventually, the composition was reacted with Tris [α-D Manos (pyrazolyl oxy) methyl] methylamine and glycodendrimer (TTP-Tr-GD) was prepared via a divergent approach to develop drug delivery system. The nanocarrier was characterized using several techniques, such as scanning electron microscopy (FE-SEM), thermal analysis (TGA), NMR, Fourier transform infrared (FT-IR), differential laser scanning (DLS), elemental mapping (EDS), and Zeta potential. Effective factors on the release of the drug delivery, including the best time to absorb, sample pH, and reaction temperature were optimized. The statistically optimized sorption efficiency (98.11%) was attained at pH = 5.5, and a contact time of 15 min. As a result of the functional groups on the surface of the TTP-Tr-GD are appropriate for simultaneous determination and high throughput analysis of drug delivery system. [ABSTRACT FROM AUTHOR]

The development of highly conjugated metalloporphyrin assemblies is a crucial step to improve their catalytic activity for optimal energy conversion processes. Herein, di‐thienyl substituted nickel(II) porphyrin is used to form a highly conjugated porphyrin structure. The resulting porphyrin‐based conjugated polymer catalyst exhibited exceptional oxygen evolution reaction "OER" performances, featuring a low onset overpotential of 266 mV and high reaction kinetics (Tafel slope of 69.9 mV/dec) under alkaline pH conditions, achieving a current density of 4.5 mA/cm2. The remarkable OER catalytic activity of porphyrin‐based conjugated polymer catalyst is attributed to the enhancement of the conjugation, which occurs through a unique process involving direct fusion of the porphyrins followed by thienyl bridging of the fused porphyrin tapes, ultimately leading to the establishment of a highly cross‐linked porphyrinic network. [ABSTRACT FROM AUTHOR]

Porphyrins hybrids have been used as models to study various energy/electron transfer processes. The linkers connecting various subunits in such hybrids are vital in establishing good electronic communication between the subunits and the azo‐bridge can be one of the efficient linkers to do so. Despite of these, the mono azo‐bridged porphyrin‐arene hybrids reported in the literature are only handful and the methods used to create them are not that efficient. In addition, the porphyrins used in this field so far contains only six‐membered meso‐substituents. By keeping these points in mind, we have developed a mild, one‐pot, work‐up‐free, high‐yielding method to synthesize mono‐azo‐bridged, porphyrin‐arene hybrids which also features porphyrins containing three five‐membered substituents like 2‐furyl or 2‐thienyl on their meso‐positions. Along with the NMR and mass characterizations, the photophysical and computational studies of all the reported hybrids are presented. The hybrids containing meso‐tris(2‐furyl/thienyl) substituted porphyrins displayed red‐shifted absorption and emission bands compared to their all‐meso‐aryl‐containing counterparts. In general, all the hybrids displayed enhanced fluorescence quantum yields compared to their precursor porphyrins. Among the series, the meso‐tris(2‐furyl) substituted porphyrin‐arene hybrids exhibited the more significant Stokes shift and small bandgap. The computational studies were in good agreement with the experimental findings. [ABSTRACT FROM AUTHOR]

The durable and economic electrocatalysts with high current density under industrial alkaline conditions are critical for advancing the industrial production of hydrogen energy by water electrolysis. The industrial highly alkaline electrolyte exacerbates the Fe dissolution of NiFe layered double hydroxide (NiFe‐LDH), leading to the dramatic degradation of stability and activity. The NiFe‐LDH intercalated Tetrakis(4‐carboxyphenyl)porphyrin (TCPP) (NiFe‐TCPP), 1,4,7,10‐Tetraazacyclododecane‐1,4,7,10‐tetraacetic acid (DOTA) (NiFe‐DOTA) and CO32− (NiFe‐CO3) are fabricated respectively for electrocatalytic water oxidation under industrial alkaline conditions. In 10 m KOH, compared to NiFe‐DOTA (335.0 mV) and NiFe‐CO3 (499.2 mV), the resultant NiFe‐TCPP exhibits the lowest overpotentials of 290.2 mV at 1000 mA cm−2. The NiFe‐TCPP also operates continuously for 1000 h at 500 mA cm−2 with near‐zero attenuation. The theoretical and experimental studies reveal that the strong coordination between conjugated carboxylate ligand TCPP and Fe of the laminate inhibits the Fe leaching by increasing the dissolution energy barriers to 4.29 eV and improving the self‐healing ability, thus enhancing the stability. Furthermore, the charge redistribution induced by the strong coordination optimizes the d‐band centers (‐2.81 eV) and decreases the reaction energy barriers (1.47 eV), thereby increasing the catalytic activity. [ABSTRACT FROM AUTHOR]

Nonaqueous organic aluminum batteries are considered as promising high‐safety energy storage devices due to stable ionic liquid electrolytes and Al metals. However, the stability and capacity of organic positive electrodes are limited by their inherent high solubility and low active organic molecules. To address such issues, here porphyrin compounds with rigid molecular structures present stable and reversible capability in electrochemically storing AlCl2+. Comparison between the porphyrin molecules with electron‐donating groups (TPP‐EDG) and with electron‐withdrawing groups (TPP‐EWG) suggests that EDG is responsible for increasing both highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels, resulting in decreased redox potentials. On the other hand, EWG is associated with decreasing both HOMO and LUMO energy levels, leading to promoted redox potentials. EDG and EWG play critical roles in regulating electron density of porphyrin π bond and electrochemical energy storage kinetics behavior. The competitive mechanism between electrochemical redox reaction and de/adsorption processes suggests that TPP‐OCH3 delivers the highest specific capacity ~171.8 mAh g−1, approaching a record in the organic Al batteries. [ABSTRACT FROM AUTHOR]

Modulating the arrangement of superstructures through noncovalent interactions has a significant impact on macroscopic shape and the expression of unique properties. Constructing π‐interaction‐driven hierarchical three‐dimensional (3D) superstructures poses challenges on account of limited directional control and weak intermolecular interactions. Here we report the construction of a 3D diamondoid superstructure, named π‐Diamond, employing a ditopic strained Z‐shaped building block comprising a porphyrin unit as bow‐limb double‐strapped with two m‐xylylene units as bowstrings. This superstructure, reminiscent of diamond's tetrahedral carbon composition, is composed of double‐walled tetrahedron (DWT) driven solely by π‐interactions. Hetero‐π‐stacking interactions between porphyrin and m‐xylylene panels drive the assembly of four building blocks predominantly into a DWT, which undergoes extension to create an adamantane unit and eventually a diamondoid superstructure wherein each porphyrin panel is shared by two neighboring tetrahedra through hetero‐π‐stacking. π‐Diamond exhibits a solid‐state fluorescent quantum yield 44 times higher than that of tetraphenylporphyrin along with excellent photocatalytic performance. The precise 3D directionality of π‐interactions, achieved through strained multipanel building blocks, revolutionizes the assembly of hierarchical 3D superstructures driven by π‐interactions. [ABSTRACT FROM AUTHOR]

ABSTRACT Photodynamic therapy (PDT) is a promising treatment for cancer. At present, the development of photosensitizers has become a hot spot for research at home and abroad. In this study, 20 porphyrin‐butylphenol compounds were synthesized, and the structures of the target compounds were analyzed by means of 1H NMR, IR, mass spectrometry, and other analytical methods. The quantum yield of the target compound as a photosensitizer for the production of singlet oxygen was determined by using a DPBF reactive oxygen probe (1,3‐diphenylisobenzofuran). The anticancer activity of the synthesized target compounds was studied using HepG2 cells and A549 cells. The results of the singlet oxygen experiments showed that the Zn metal chelated compound had better singlet oxygen production than the free‐base porphyrin. The cellular activity assays showed that the metal‐chelated compounds exhibited better in vitro antitumor activity. [ABSTRACT FROM AUTHOR]

Porphyrins‐based porous organic polymers (POP) were widely used in photocatalytic oxidation under visible light owing to their superiority in the activation of oxygen. In contrast, the efficiency is usually limited due to the fast recombination and slow electron transfer. Herein, we report the use of a trioporphyrins‐based covalent triazine framework (Por‐CTF) as visible‐light‐active photocatalyst for the coupling oxidative of amines to imines at room temperature. By incorporating the π‐conjugated porphyrin building block led to the enhanced electron transport between molecules, and the extended recombination time of excited electrons. The photocatalytic efficiency of Por‐CTF is superior to that of polymer in absence of triazine framework (POP‐TSP), which was prepared by radical polymerization using tetra‐(4‐vinylphenyl) porphyrin (TSP) as monomer. Por‐CTF catalyst presented excellent efficiency for various primary amines and stability. This work provides a reasonable guidance of catalyst molecular structure design for enhancing efficiency in the photocatalytic oxidation. [ABSTRACT FROM AUTHOR]

In the present work, we have synthesized sulfone-bridged tetraphenyl porphyrin, 2D polymer 'P' (C44H28N4OySx)n through a one-pot reaction of tetra(p-bromophenyl) porphyrin, S with sulfur powder in DMF. The polymer 'P' has been further reacted with erythrosine B for the fabrication of composite photocatalyst, C (C65H37N4NaOySx)n using donor– acceptor conjugation protocol. Herein, both compounds (P & C) have been well characterized by MAS 13C-NMR, XPS, IR, powder XRD, TGA, SEM-EDX, UV-Vis spectra, and Cyclic Voltammetry. Due to the low HOMO-LUMO band gap energy, the applicability of the composite photocatalyst (C, 2.1 eV) has been studied in terms of oxidation of sulfide to sulfoxide. The present work shows a promising route for the development of sulfone-bridged 2D porphyrin covalent organic framework (COF) and its composite photocatalyst as well as its usage in photocatalytic sulfoxidation reaction. [ABSTRACT FROM AUTHOR]

Two‐dimensional porphyrin‐based covalent–organic frameworks (2D‐por‐COFs) have gained significant attention as attractive platforms for efficient solar light conversion into hydrogen production. Herein, it is found that introducing transition metal zinc and polyethylene glycol (PEG) into 2D‐por‐COFs can effectively improve the photocatalytic hydrogen evolution performance. The photocatalytic hydrogen evolution rate of ZnPor‐COF is 2.82 times higher than that of H2Por‐COF. Moreover, ZnPor‐COF@PEG has the highest photocatalytic hydrogen evolution efficiency, which is 1.31 and 3.7 times that of pristine ZnPor‐COF and H2Por‐COF, respectively. The filling of PEG makes the layered structure of COFs more stable. PEG reduces the distortion and deformation of the carbon skeleton after the experiment of photocatalytic hydrogen evolution. The layered stacking and crystallization of 2D‐por‐COFs are also enhanced. Meanwhile, the presence of PEG also accelerates the transfer of excited electrons and enhances the photocatalytic hydrogen evolution activity. This strategy will provide valuable insights into the design of 2D‐por‐COFs as efficient solid photocatalysts for solar‐driven hydrogen production. [ABSTRACT FROM AUTHOR]

The influence of the architecture of NH2-peripheral substitution of porphine derivatives on the intersystem T1 → S0-transition energy was studied theoretically. The molecular conformations of 15 porphine derivatives and 8 Zn-porphine derivatives in the ground singlet (S0) and lowest triplet (T1) states were optimized, the molecular orbital energies were determined, and the energies of the T1 → S0 transition were calculated using quantum chemical methods. The T1 → S0-transition energy was found to decrease from 11,700 to 6200 cm–1 upon increasing the number of NH2 groups in the macrocycle Cm-positions. The T1 → S0-transition energy was a linear function of the weighted sum of inductive and resonant Hammett constants 0.2σI + 0.8σR of the substituents. The ratio of inductive and resonant contributions of the NH2 groups depended on the method of attachment to the macrocycle, with the contribution of resonant interactions decreasing with increasing spacer length. The main reason for the bathochromic shift of the T1 → S0 transition was a significant increase in the energy of the b1-orbital, which had antinodes on the macrocycle Cm atoms. The dependence also held for Zn-porphyrins with the same peripheral substitution architecture. The energy of the T1 → S0 transition was noted to differ for both NH tautomers and conformers differing in the position of NH2 groups relative to the macrocycle mean plane. The calculations showed that experimental studies of aminoporphyrins were promising for obtaining new phosphors in the IR spectral region. A method for predicting the T1 → S0-transition energy for the synthesis of compounds with the required spectral and luminescent characteristics was proposed based on the results. [ABSTRACT FROM AUTHOR]

Overexpression of recombinant Bacillus cereus TSPO (Bc TSPO) in E. coli bacteria leads to its recovery with a bound hemin both in bacterial membrane (MB) and inclusion bodies (IB). Unlike mouse TSPO, Bc TSPO purified in SDS detergent from IB is well structured and can bind various ligands such as high-affinity PK 11195, protoporphyrin IX (PPIX) and δ-aminolevulinic acid (ALA). For each of the three ligands, 1H–15N HSQC titration NMR experiments suggest that different amino acids of Bc TSPO binding cavity are involved in the interaction. PPIX, an intermediate of heme biosynthesis, binds to the cavity of Bc TSPO and its fluorescence can be significantly reduced in the presence of light and oxygen. The light irradiation leads to two products that have been isolated and characterized as photoporphyrins. They result from the addition of singlet oxygen to the two vinyl groups hence leading to the formation of hydroxyaldehydes. The involvement of water molecules, recently observed along with the binding of heme in Rhodobacter sphaeroides (Rs TSPO) is highly probable. Altogether, these results raise the question of the role of TSPO in heme biosynthesis regulation as a possible scavenger of reactive intermediates. [Display omitted] • Hemin is bound to Bc TSPO overexpressed in E. coli. • SDS-purified Bc TSPO is structured and binds ligands. • Purified Bc TSPO is functional and degrades PPIX upon UV light irradiation. • Oxygen-dependent PPIX degradation generates non-fluorescent products. • Products generated by ROS are hydroxyaldehydes. [ABSTRACT FROM AUTHOR]

Porphyrin–polymer systems are promising materials for their use in biotechnology, biochemistry, and medicine. The creation of composite materials from porphyrins expands the possibilities of using both high molecular weight compounds and porphyrins. Polylactide–porphyrin film samples obtained by solution watering method are studied in this work. It was found that the density of the film compositions decreases with an increase in an amount of porphyrin in the polymer matrix. A Soret peak of porphyrin immobilized into the polylactide matrix splits (425 and 447 nm) and shifts bathochromically. The addition of 5,10,15,20-tetrakis(4-n-hexyloxyphenyl)porphyrin changes the elastic behavior and strength properties. Shear modulus, elastic modulus, and tensile strength decrease with an increase in an amount of porphyrin in the polylactide matrix. Relative elongation at break increases slightly, and the Poisson's ratio is almost unchanged compared to those of starting polylactide. [ABSTRACT FROM AUTHOR]

Oxidovanadium meso‐tetrakis(3,4,5‐trimethoxyphenyl) porphyrin [VO(T(OMe)3PP)] (Complex 1) was prepared. The oxidation product of Complex 1 has been characterized by cyclic voltammetry (CV), UV–visible spectrophotometer, electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) by the addition of SbCl5 to Complex 1. There is a one‐electron oxidation product in Complex 1 that creates π–cation radicals in CV data. This is supported by an IR spectrophotometer. Subsequent EPR spectra verified the initiation of the π–cation monoradical, which subsequently transforms into a triplet state where S = 1. DNA binding and antibacterial analysis with Complex 1 have also been analysed. In the DNA‐binding analysis, the CV data confirm the interaction between Complex 1 and DNA. Furthermore, the fact that Complex 1 is more effective at killing bacteria shows that the metal ion's chelation with the porphyrin ligand makes it more lipophilic. [ABSTRACT FROM AUTHOR]

Metal–tetrapyrrole cofactors are involved in multiple cellular functions, and chelatases are key enzymes for the biosynthesis of these cofactors. CfbA is an ancestral, homodimeric‐type class II chelatase which is able to use not only Ni2+ as a physiological metal substrate, but also Co2+ as a nonphysiological substrate with higher activity than for Ni2+. The Ni/Co‐chelatase function found in CfbA is also observed in SirB, a descendant, monomeric‐type class II chelatase. This is despite the distinct active site structure of CfbA and SirB; specifically, CfbA shows a unique four His residue arrangement, unlike other monomeric class II chelatases such as SirB. Herein, we studied the Ni‐chelatase activity of SirB variants R134H, L200H, and R134H/L200H, the latter of which mimics the His alignment of CfbA. Our results showed that the SirB R134H variant exhibited the highest Ni‐chelatase activity among the SirB enzymes, which in turn suggests that the position of His134 could be more important for the Ni‐chelatase activity than that of His200. The SirB R134H/L200H variant showed lower activity than R134H, despite the four His residues found in SirB R134H/L200H. CD spectroscopy showed secondary structure denaturation and a slight difficulty in Ni‐binding of SirB R134H/L200H, which may be related to its lower activity. Finally, a docking simulation suggested that the His134 of the SirB R134H variant could function as a base catalyst for the Ni‐chelatase reaction in a class II chelatase architecture.

This research systematically investigates the impact of porphyrin and chlorophyll dyes on Dye-Sensitized Solar Cells (DSSC) performance, aims to achieve maximum solar cell efficiency. This investigation involved the use of Fluorine-doped Tin Oxide (FTO) coating with TiO2–ZnO composite, incorporating Al doping, and introducing variations in the concentration of chlorophyll SP and porphyrin (2:2:0.1 and 2:2:0.2). Synthesis of Al-doped ZnO was carried out via the sol-gel method, which involves mixing and heating at 65°C, followed by degradation at 150°C. TiO2 and ZnO: Al composites were formed using the sonication method at 45°C for 60 minutes. This study evaluates the impact of dyes on the growth of TiO2 and ZnO: Al composites and examines their characteristics - including UV-Vis, band gap, current versus voltage curves, DSSC efficiency-using EDX, and FTIR analyses of solar cells. The DSSC efficiency testing utilizes a photon light source from a halogen lamp with an intensity of 328-580 lux. The results showed that DSSC based on TiO2–ZnO: Al + chlorophyll produced an efficiency of 13.3%, while porphyrin (2:2:0.1) and (2:2:0.2) produced an efficiency of 8.9% and 13.9%, respectively. In conclusion, this study shows that adding dye to the TiO2–ZnO: Al composite significantly improves DSSC performance and shows optimal characteristics. The highest DSSC efficiency of 13.9% underscores the interdependence of absorber layer quality with photovoltaic performance, providing valuable insights for future solar cell design and optimization.

This study investigates the synthesis of tetra‐ and octa‐O‐fused porphyrinoids employing an oxidative O‐annulation approach through C−H activation. Despite encountering challenges such as overoxidation and instability in conventional solution protocols, successful synthesis was achieved on Au(111) surfaces under ultra‐high vacuum (UHV) conditions. X‐ray photoelectron spectroscopy, scanning tunneling microscopy, and non‐contact atomic force microscopy elucidated the preferential formation of pyran moieties via C−O bond formation and subsequent self‐assembly driven by C−H⋅⋅⋅O interactions. Furthermore, the O‐annulation process was found to reduce the HOMO–LUMO gap by lifting the HOMO energy level, with the effect rising upon increasing the number of embedded O‐atoms. [ABSTRACT FROM AUTHOR]

This work reported “trinitarian” porphyrin nanobelts, contained hetero‐trimetal ions. The high‐resolution mass spectrometry and X‐ray crystallography proved PNBNiCuPd consisting of three different bent porphyrin(2.1.2.1) metal complex moieties. The redox properties indicate porphyrin nanobelts demonstrate the multielectron donating and accepting properties, more than nine redox processes. [ABSTRACT FROM AUTHOR]

Electrocatalytic reduction of nitrate to ammonia (NO 3 RR) is one of the effective methods to treat environmental pollution caused by nitrate and to produce valuable product of ammonia at the same time. Single-atom catalysts based two-dimensional metalloporphyrin monolayers as effective catalysts for NO 3 RR is investigated in this study by first-principles calculations and interpretable machine learning. Trough high-throughput four step screening procedures, three catalysts (NbPP, TaPP and WPP) finally stood out with high stability, catalytic selectivity and activity for NH 3 production (U L = −0.24, −0.28 and −0.33 V respectively). With Δ G *NO3 and d band center as descriptors, volcano curves were construct to explain the activity trend, in which the three catalysts are just located near the top of the volcano. An effective model for the catalyst performance was built by machine learning to illustrate the possible relationship between adsorption free energy of nitrate and the intrinsic properties of the catalyst, which shows Q TM , N, χ and d TM-N have significant effect on catalyst performance. In all, this study screened effective catalyst and provides theoretical guidance for the rational design of SACs for NO 3 RR. • SACs based on 2D metalloporphyrin monolayers for NO 3 RR investigated. • Four step procedures screened NbPP, TaPP and WPP with high-performance. • Effective model for the catalyst performance built with machine learning. • Q TM , N, χ and d TM-N have significant joint effect on catalyst performance. [ABSTRACT FROM AUTHOR]

The novel and exciting class of porphyrin‐based compounds are the main group coordination‐driven porphyrins (MGCPs) with a central main group element into the porphyrin macrocycle. MGCPs have unique properties, reactivity, and potential applications in catalysis, sensing, biomedicine etc. This comprehensive review article discusses recent advances in the field of main group coordination driven porphyrins and explores some of its potential uses in solar cells, catalysis, antimicrobial, optoelectronic devices, sensing, and catalysis. The addition of main group elements to porphyrin systems has resulted in the production of entirely novel compounds that have intriguing qualities including increased stability and catalytic activity. Significant modifications in these unique compounds features are apparent through the analysis of their structural properties. It encompasses FTIR, proton NMR, electrical and optical characterisation in addition to an electrochemical analysis of those parameters. They serve as significant building blocks for the creation of cutting‐edge materials and technologies in a variety of scientific and technical disciplines because to their special qualities and adaptability. Researchers working in the domains of coordination chemistry, catalysis, and materials science will find this study to be of interest since it offers a thorough examination of current developments in main group coordination driven porphyrins and their prospective applications. Overall, main group porphyrins are used in many different fields, such as sensing, catalysis, and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Aromaticity and antiaromaticity are foundational principes in organic chemistry, regularly invoked to explain stability, structure, and magnetic and electronic properties. There are ongoing challenges in assigning molecules as aromatic or antiaromatic using optical spectroscopy. Here we report spectroelectrochemical and computational analyses of porphyrin (18π neutral, aromatic) and norcorrole (16π neutral, antiaromatic), and their oxidized (16π porphyrin dication) and reduced (norcorrole 18π dianion) forms. Our results show that while the visible spectra are characteristic of (anti)aromaticity consistent with Hückel's rules, the IR spectra are much less informative, owing to the relative rigidity of norcorrole. The results have implications for the assignment of (anti)aromaticity in both ground‐state and time‐resolved spectra. [ABSTRACT FROM AUTHOR]

Photoactive artificial nanocatalysts that mimic natural photoenergy systems can yield clean and renewable energy. However, their poor photoabsorption capability and disfavored photogenic electron–hole recombination hinder their production. Herein, we designed two nanocatalysts with various microstructures by combining the tailored self-assembly of the meso-tetra(p-hydroxyphenyl) porphine photosensitizer with the growth of titanium dioxide (TiO2). The porphyrin photoabsorption antenna efficiently extended the absorption range of TiO2 in the visible region, while anatase TiO2 promoted the efficient electron–hole separation of porphyrin. The photo-induced electrons were transferred to the surface of the Pt co-catalyst for the generation of hydrogen via water splitting, and the hole was utilized for the decomposition of methyl orange dye. The hybrid structure showed greatly increased photocatalytic performance compared to the core@shell structure due to massive active sites and increased photo-generated electron output. This controlled assembly regulation provides a new approach for the fabrication of advanced, structure-dependent photocatalysts. [ABSTRACT FROM AUTHOR]

Ultrafast lasers have significantly contributed to the advancement of research and technology; however, high‐intensity lasers bring potential risks to precision instruments and the human eye. Developing optical limiting (OL) devices capable of reasonably controlling laser energy to an acceptable energy level is imperative. Nevertheless, achieving both exceptional OL performance and broad‐spectrum laser intensity tunability proves highly challenging. In this work, the synthesis of a porphyrin‐based 2D polymer (Por‐2DP) using a template‐assisted self‐coupling polymerization, constructing a 2D framework through the carbon‐carbon single bond coupling of porphyrin monomer is presented. The resultant Por‐2DP demonstrates remarkable broadband nonlinear absorption performance, spanning the visible and near‐infrared spectral regions under an ultrafast pulse laser (35 fs) for the first time. OL thresholds at excitation wavelengths of 515, 800, and 1550 nm are determined to be 1.44, 0.48, and 0.54 mJ cm−2, respectively, surpassing reported 2D materials to date. Additionally, the Por‐2DP exhibits prominent photostability, enabling sustained operation under intense light conditions for a long time, thereby enhancing OL practical applicability. This study not only introduces a novel OL material and device but also promotes the application of innovative 2D organic polymers in NLO field. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries (AZIBs) possess high theoretical capacity and good safety, making them highly hopeful for large‐scale energy storage applications. Nevertheless, the uncontrolled growth of Zn dendrites on anode significantly reduces the cycle life of AZIBs. In this study, a series of porphyrin‐based porous organic polymers (CuTAPP‐NTCDA‐POP and ZnTAPP‐NTCDA‐POP) are synthesized using aminophenylporphyrin (TAPP) and aromatic dianhydride, which are served as porous protective coating layers for Zn anode. The coating effectively prevents the formation of Zn dendrites and guides the deposition of Zn2+ because of the abundance of zincophilic sites. As expected, the symmetric cells equipped with the optimum ZnTAPP‐NTCDA‐POP@Zn anode demonstrate a longer cycle life of over 1200 h at 0.5 mA cm−2 compared to bare Zn (64 h). Moreover, when the ammonium vanadate (NHVO) cathode is coupled with ZnTAPP‐NTCDA‐POP@Zn anode, the resulting full cell displays superior cycle stability that sustains over 350 cycles with a higher invertible capacity (225 mAh g−1 at 1 A g−1). This performance surpasses that of a full cell equipped with just a bare Zn anode. This work proposes a viable strategy to address Zn dendrites, presenting a promising horizon for the widespread application of AZIBs. [ABSTRACT FROM AUTHOR]

Selective oxidation of hydrocarbons using molecular oxygen as sole oxidant under mild conditions remains a challenging task. In this context, metal‐organic frameworks (MOFs) have been widely used in various oxidation reactions due to their porosity, high surface area and designability. However, the slow diffusion of substrates/products in micropores of three‐dimensional (3D) bulk MOFs hinders the efficient catalytic performance of such materials. Herein an ultrathin two‐dimensional (2D) porphyrin‐based Zr‐MOF nanosheet (Zr‐TCPP) is synthesized through modulator‐control strategy. Subsequently, various metal ions are anchored into the porphyrin ring by post synthesis modification to afford a series of 2D Zr‐TCPP(M) (M=Mn, Fe, Co, Ni, Cu and Zn). Various structural characterization techniques indicate Zr‐TCPP(M) is nanoflower structure with ultrathin nanoplate petals which provides fully exposed accessible active sites. Among them, Zr‐TCPP(Fe) shows excellent catalytic performance in styrene epoxidation reactions and benzylic C−H oxidation reactions using O2 as sole oxidant under ambient temperature and pressure. The remarkable activity arises from high density of exposed porphyrin‐Fe active sites, low diffusion barriers for substrates and products, as well as a similar homogeneous reaction space. Furthermore, Zr‐TCPP(Fe) nanosheet is easily recycled by centrifugation and reused at least five times without significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

In this paper, the novel PCN-224/cloisite-30B composite is prepared through the solvothermal method. Cloisite-30B, a natural, nonpoisonous, and inexpensive substance, has been composited with porphyrinic-based-MOF for the first time. The mentioned composite has been characterized by X-ray diffraction analysis, Fourier-transform infrared spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Also, the quadratic model for predicting methylene blue (MB) removal efficiency is presented (R2 = 0.9984, R2adj = 0.9954). Moreover, the optimum condition for MB adsorption has been assessed through Design-Expert software (80 initial dye concentration, 20 mg adsorbent, 30 min adsorption time, pH = 7). At the optimum condition, the adsorption capacity of adsorbent toward four other dyes has been studied, including methyl orange (MO), rhodamine B (RhB), congo red (CR), and eriochrome black T (EBT). The adsorption (Langmuir, Freundlich, and Temkin model) and kinetic (first and second order) study were calculated based on non-linear equations. PCN-224/cloisite-30B is an efficient adsorbent in dye removal and acts selectively when it is in contact with anionic and cationic species with close molecular size. Furthermore, the composite is highly recyclable, after ten washing cycles, it has the same efficiency as the first cycle in MB removal. [ABSTRACT FROM AUTHOR]

The liver, a pivotal organ in human metabolism, serves as a primary site for heme biosynthesis, alongside bone marrow. Maintaining precise control over heme production is paramount in healthy livers to meet high metabolic demands while averting potential toxicity from intermediate metabolites, notably protoporphyrin IX. Intriguingly, our recent research uncovers a disrupted heme biosynthesis process termed 'porphyrin overdrive' in cancers that fosters the accumulation of heme intermediates, potentially bolstering tumor survival. Here, we investigate heme and porphyrin metabolism in both healthy and oncogenic human livers, utilizing primary human liver transcriptomics and single-cell RNA sequencing (scRNAseq). Our investigations unveil robust gene expression patterns in heme biosynthesis in healthy livers, supporting electron transport chain (ETC) and cytochrome P450 function without intermediate accumulation. Conversely, liver cancers exhibit rewired heme biosynthesis and a massive downregulation of cytochrome P450 gene expression. Notably, despite diminished drug metabolism, gene expression analysis shows that heme supply to the ETC remains largely unaltered or even elevated with patient cancer progression, suggesting a metabolic priority shift. Liver cancers selectively accumulate intermediates, which are absent in normal tissues, implicating their role in disease advancement as inferred by expression analysis. Furthermore, our findings in genomics establish a link between the aberrant gene expression of porphyrin metabolism and inferior overall survival in aggressive cancers, indicating potential targets for clinical therapy development. We provide in vitro proof-of-concept data on targeting porphyrin overdrive with a drug synergy strategy. [ABSTRACT FROM AUTHOR]

Metal–tetrapyrrole cofactors are involved in multiple cellular functions, and chelatases are key enzymes for the biosynthesis of these cofactors. CfbA is an ancestral, homodimeric‐type class II chelatase which is able to use not only Ni2+ as a physiological metal substrate, but also Co2+ as a nonphysiological substrate with higher activity than for Ni2+. The Ni/Co‐chelatase function found in CfbA is also observed in SirB, a descendant, monomeric‐type class II chelatase. This is despite the distinct active site structure of CfbA and SirB; specifically, CfbA shows a unique four His residue arrangement, unlike other monomeric class II chelatases such as SirB. Herein, we studied the Ni‐chelatase activity of SirB variants R134H, L200H, and R134H/L200H, the latter of which mimics the His alignment of CfbA. Our results showed that the SirB R134H variant exhibited the highest Ni‐chelatase activity among the SirB enzymes, which in turn suggests that the position of His134 could be more important for the Ni‐chelatase activity than that of His200. The SirB R134H/L200H variant showed lower activity than R134H, despite the four His residues found in SirB R134H/L200H. CD spectroscopy showed secondary structure denaturation and a slight difficulty in Ni‐binding of SirB R134H/L200H, which may be related to its lower activity. Finally, a docking simulation suggested that the His134 of the SirB R134H variant could function as a base catalyst for the Ni‐chelatase reaction in a class II chelatase architecture. [ABSTRACT FROM AUTHOR]

A hitherto unknown class of C4‐symmetric Caryl−Cβ (C3, C8, C13, C18) axially chiral porphyrins has been synthesized and the application of their iridium (Ir) complexes in catalytic asymmetric C(sp3)−H functionalization is documented. Cyclotetramerization of enantioenriched axially chiral 2‐hydroxymethyl‐3‐naphthyl pyrroles under mild acidic conditions affords, after oxidation with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ), the C4‐symmetric α,α,α,α‐atropenantiomer as an only isolable diastereomer. Both regioisomeric Ir(Por*)(CO)(Cl) complexes catalyze the carbene C−H insertion reaction affording the same enantiomer, albeit with slight difference in enantioselectivity. With the optimum Ir‐complex 3 e, the 2‐substituted arylacetic acid derivatives were generated from diazo compounds and cyclohexadiene in excellent yields and enantioselectivities. [ABSTRACT FROM AUTHOR]

Two diphosphanes with variable-length ligands tested as nucleophiles to prepare isoporphyrin copolymers in the presence of ditolylporphyrin of zinc (ZnT2P) prevented the oxidation of the diphosphine ligand. This paper demonstrates the power of this approach and describes the photoelectrocatalytic properties. The obtained copolymers were characterized by UV–vis spectroscopy, X-ray photoelectron spectroscopy, atomic force micrograph (AFM), EQCM (Electrochemical Quartz Cristal Microbalance) and electrochemistry. Their impedance properties (EIS) were studied and their photovoltaic performances were also investigated by photocurrent transient measurements under visible light irradiation. [ABSTRACT FROM AUTHOR]

Heme, an iron-containing tetrapyrrole, is essential in almost all organisms. Heme biosynthesis needs to be precisely regulated particularly given the potential cytotoxicity of protoporphyrin IX, the intermediate preceding heme formation. Here, we report on the porphyrin intermediate accumulation within the tumor microenvironment (TME), which we propose to result from dysregulation of heme biosynthesis concomitant with an enhanced cancer survival dependence on mid-step genes, a process we recently termed "Porphyrin Overdrive". Specifically, porphyrins build up in both lung cancer cells and stromal cells in the TME. Within the TME's stromal cells, evidence supports cancer-associated fibroblasts (CAFs) actively producing porphyrins through an imbalanced pathway. Conversely, normal tissues exhibit no porphyrin accumulation, and CAFs deprived of tumor cease porphyrin overproduction, indicating that both cancer and tumor-stromal porphyrin overproduction is confined to the cancer-specific tissue niche. The clinical relevance of our findings is implied by establishing a correlation between imbalanced porphyrin production and overall poorer survival in more aggressive cancers. These findings illuminate the anomalous porphyrin dynamics specifically within the tumor microenvironment, suggesting a potential target for therapeutic intervention. [ABSTRACT FROM AUTHOR]

In this study, porphyrin was prepared and doped with chitosan biopolymer using the solution casting process at various weight percentages (5 and 10 wt% CS-PP). The structural characteristics of the nanocomposite material were carefully examined using FTIR, SEM, and XRD. The presence of the distinctive chitosan peaks was confirmed by FTIR spectra; these peaks were altered by contact with porphyrin molecules. The chitosan surface displayed noticeable morphological changes on the SEM graphs, which result from surface interaction with porphyrin active sites. Moreover, XRD showed structural enhancement in the crystallinity of chitosan by incorporating porphyrin molecules. The nanocomposite films' optical characteristics, including refractive index, energy band gap, and optical dispersion parameters, were also investigated. It was observed that the band gap of pure chitosan is significantly reduced upon the addition of porphyrin nanocomposite. The increase of refractive index with increasing porphyrin nanocomposite doping is evidence for the formation of new energy states and thus decreasing the energy band gap of chitosan. [ABSTRACT FROM AUTHOR]

This research describes the functionalization of polymer-matrix-trapping porphyrins, considering that the transcendental properties of meso-substituted porphyrins, such as optical and chemical stability, combined with the strength of the polymers, can produce photoactive advanced polymeric networks. Polystyrene (PS) and O,O´-bis-(2-aminopropyl)-polyethyleneglycol-300 (2NH2peg300, APEG), or their combination, were used to confine the meso-substituted porphyrin species 5,10,15,20-tetrakis(4'-carboxy-1,1'-biphenyl-4-yl)porphyrin and 5,10,15,20-tetrakis((pyridin-4-yl)phenyl)porphyrin. The samples were characterized by Fourier-transform infrared (FTIR), X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) and fluorescence spectroscopies. The absorption and emission properties of the materials were compared to those of their respective porphyrin solutions. The fluorescence was preserved in the obtained composite through a mixture of polymers, PS, and APEG, yielding translucent polymeric networks. Moreover, analysis of individual polymeric assemblies by molecular docking was performed to support the understanding of the experimental findings. This analysis corroborates that the stronger the estimated binding energies, the stronger the interactions that occur between porphyrin and the polymer via non-polar covalent bonds. [ABSTRACT FROM AUTHOR]