Search

Aerobic oxidation of olefins without any co‐reductant and high temperature was studies in the presence of nano and bulky Fe‐porphyrin in a comparative manner. Nano‐particles of Fe‐porphyrin were obtained via ultrasound irradiation. The results show higher catalytic efficiency of nano‐catalyst (turnover number of 1300) with respect to the bulk catalyst (turnover number of 600) in the oxidation of cyclohexene with molecular oxygen at room temperature. [ABSTRACT FROM AUTHOR]

Biomimetic metalloporphyrin complexes have been employed in a number of catalytic oxidation reactions by utilizing terminal oxidants such as iodosylarenes (ArIO). Although high‐valent metal‐oxo species have been considered as the reactive intermediates, their precursors, metal‐iodosylarene adduct species, also exhibit intriguing oxidation capability under certain conditions. However, late transition metal porphyrin‐oxidant adduct species have not been explored in oxidation reactions yet. Herein, we report the synthesis, characterization and reactivity studies of cobalt(III) porphyrin‐ArIO adduct complexes. These adduct species exhibit moderate oxidation capability in electron transfer reactions. More interestingly, addition of Brønsted acid or Lewis acid facilitated the O−I bond cleavage, resulted in the formation of cobalt(III) porphyrin π‐cation radical species, which is much more reactive than the corresponding adduct species in electron transfer reactions. Kinetic studies and theoretical calculations demonstrate that the O−I bond cleavage is triggered in the presence of acid, affording the porphyrin ligand oxidation while the formation of high‐valent cobalt‐oxo species is prohibited due to the "oxo‐wall" for late transition metals. This study provides a novel model of a late transition metal‐iodosylarene adduct species as an active oxidant in oxidation reactions, while in the cases of iron and manganese complexes, high‐valent metal‐oxo species are generated. [ABSTRACT FROM AUTHOR]

Nanographenes, which feature at least one dimension smaller than 100 nm, are drawing interdisciplinary attention. Understanding the interplay between structure and properties is, however, still in its infancy. Molecular nanographenes are much better suited to fill this knowledge gap than graphene quantum dots or nanoribbons. Their bottom‐up synthesis allows atomic precision and, thereby, assists in handling structure and connecting it with properties. Herein, the effects of nitrogen‐doping and lateral π‐extension in molecular nanographenes and in their coordination complexes with ruthenium porphyrins are investigated. The presence of just nitrogen resulted in an increase of the fluorescence quantum yield, without, however, affecting the energy levels. Lateral π‐extension of the nanographenes, instead, resulted in a modulation of the excited states energy, which leads to a thermally‐activated dual fluorescence with quantum yields as high as 61%. In the corresponding coordination complexes, lateral π‐extension resulted in a ping‐pong energy transfer cascade, that is, from the nanographene to the metalloporphyrin and back to the nanographene. The results help to directly rationalize properties observed in both graphene quantum dots and nanoribbons. Moreover, they prove that molecular nanographenes are appealing components for solar energy conversion schemes, where the modulation of inter‐component energy transfer is of utmost importance. [ABSTRACT FROM AUTHOR]

The Faraday efficiency of CO 2 electroreduction to CO catalyzed by metalloporphyrins (MTPP, M = Fe, Co, Cu, Zn and Ni) is linearly related to the reaction energy barrier of the first proton-coupled electron reduction. [Display omitted] • Five metalloporphyrins(MTPPs) with different metal centers are compared for CO 2 RR. • CO 2 RR mechanism on MTPPs are calculated by first-principles calculations. • CoTPP exhibits the best CO 2 RR activity and selectivity. • The results of theoretical calculation are well verified by experimental tests. • The linear correlation between the selectivity of CO and the key energy barrier is revealed. Metal-functionalized porphyrin-like graphene structures are promising electrocatalysts for carbon dioxide reduction reaction (CO 2 RR) as their metal centers can modulate activity. Yet, the role of metal center of metalloporphyrins (MTPPs) in CO 2 reaction activity is still lacking deep understanding. Here, CO 2 RR mechanism on MTPPs with five different metal centers (M = Fe, Co, Cu, Zn and Ni) are examined by first-principles calculations. The *COOH formation is the rate determined step on the five MTPP structures, and the CoTPP exhibits the best CO 2 RR activity while ZnTPP and NiTPP are the worst, which is also verified by our experiment. The CO 2 RR activity is controlled by adsorption states of intermediates (*CO, *COOH), i.e., chemisorption (e.g., on CoTPP) and physisorption (on ZnTPP and NiTPP) of intermediates will lead to good and poor activity, respectively. The deeper the d- band center of the porphyrin ring complexed metal atom, the weaker bonding of MTPP with CO and COOH. Theoretical calculations and experimental results indicate that MTPPs with Co and Fe centers lead to a reduction in the energy barriers for the two uphill reaction steps in the electrocatalytic CO 2 reduction process, thereby enhancing CO 2 reduction electrocatalytic activity. Faradaic efficiency of CO is correlated with the reaction energy barrier of the first proton-coupled electron reduction process, displaying a strong linear correlation. This work provides a fundamental understanding of MTPPs used as electrocatalysts for CO 2 RR. [ABSTRACT FROM AUTHOR]

In the context of water electrolysis being highlighted as a promising technology for the large-scale sustainable production of hydrogen, the water-splitting electrocatalytic properties of an asymmetrically functionalized A3B zinc metalated porphyrin, namely, Zn(II) 5-(4-pyridyl)-10,15,20-tris(4-phenoxyphenyl)-porphyrin, were evaluated in a wide pH range. Two different electrode manufacturing procedures were employed to outline the porphyrin's applicative potential for the O2 and H2 evolution reactions (OER and HER). The electrode, manufactured by coating the catalyst on a graphite support from a dimethylsulfoxide solution, displayed electrocatalytic activity for the OER in an acidic electrolyte. An overpotential value of 0.44 V (at i = 10 mA/cm2) and a Tafel slope of 0.135 V/dec were obtained. The modified electrode that resulted from applying a Zn(II)-porphyrin-containing catalyst ink onto the same substrate type was identified as a bifunctional water-splitting catalyst in a neutral medium. OER and HER overpotentials of 0.78 and 1.02 V and Tafel slopes of 0.39 and 0.249 V/dec were determined. This is the first Zn(II)-porphyrin to be reported as a heterogenous bifunctional water-splitting electrocatalyst in neutral aqueous electrolyte solution and is one of very few porphyrins behaving as such. The TEM analysis of the porphyrin's self-assembly behavior revealed a wide variety of architectures. [ABSTRACT FROM AUTHOR]

The reduction of carbon dioxide (CO2) using porphyrin‐containing 2D covalent organic frameworks (2D‐COFs) catalysts is widely explored nowadays. While these framework materials are normally fabricated as powders followed by their uncontrolled surface heterogenization or directly grown as thin films (thickness >200 nm), very little is known about the performance of substrate‐supported single‐layered (≈0.5 nm thickness) 2D‐COFs films (s2D‐COFs) due to its highly challenging synthesis and characterization protocols. In this work, a fast and straightforward fabrication method of porphyrin‐containing s2D‐COFs is demonstrated, which allows their extensive high‐resolution visualization via scanning tunneling microscopy (STM) in liquid conditions with the support of STM simulations. The as‐prepared single‐layered film is then employed as a cathode for the electrochemical reduction of CO2. Fe porphyrin‐containing s2D‐COF@graphite used as a single‐layered heterogeneous catalyst provided moderate‐to‐high carbon monoxide selectivity (82%) and partial CO current density (5.1 mA cm−2). This work establishes the value of using single‐layered films as heterogene ous catalysts and demonstrates the possibility of achieving high performance in CO2 reduction even with extremely low catalyst loadings. [ABSTRACT FROM AUTHOR]

5,10,15,20-tetramethoxyphenylporphyrinatotin (IV) (SnTMPP) was synthesised. SnTMPP exhibited Soret band at 432 nm and emission peaks at 629 and 682 nm. The fluorescence intensity of SnTMPP was quenched in the presence of guanine linearly in the range 4 × 10–9 M to 7.2 × 10–8 M and the quenching response was found to be stable even in the presence of other nucleosides such as adenine, cytosine, uracil, thymine, alanine, aspartic acid and ascorbic acid. The detection limit was found to be 0.17 nM and the mechanism behind the decrease in the fluorescence intensity of SnTMPP in the presence of guanine is due to dynamic quenching, which was confirmed by cyclic voltammetric studies and life time studies. The CV studies illustrates the possibilty for an electron transfer between the guanine and the electron deficient metal core of SnTMPP. [ABSTRACT FROM AUTHOR]

Aqueous Zn metal batteries hold significant promise for large‐scale energy storage owing to their high safety and low cost. Nevertheless, severe corrosion and uncontrollable dendrite growth hinder the cyclic stability of Zn metal anodes. Herein, a porphyrin‐Zn(II) (ZnTBPP) based multifunctional artificial layer to stabilize Zn anodes by suppression of hydrogen evolution reactions is designed. This hydrophobic interfacial layer repels active water molecules and facilitates the electron transfer from Zn interface to the ZnTBPP layer, thereby increasing the inherent hydrogen evolution potential of Zn anodes. Differential charge density maps reveal that the electron cloud density of the charge transfer layer within the ZnTBPP layer is delocalized due to the electron‐withdrawing effect of Br‐containing functional groups in the ZnTBPP ligands, depleting the interfacial electrons of Zn metal anodes. As a result, H* exhibits a higher Gibbs free energy (∆GH*) of 0.75 eV on Zn with a ZnTBPP coating layer in contrast to bare Zn (0.55 eV), effectively suppressing H2 production. Specifically, the H2 evolution rate of ZnTBPP@Zn (4.06 µmol h−1 cm−2) is ≈2.2 times lower than that of bare Zn. The ZnTBPP@Zn//NaV3O8·1.5H2O full cells exhibit an ultra‐long cycling life of 10 000 cycles at 10 A g−1. [ABSTRACT FROM AUTHOR]

In this study, the electro-oxidation reaction of ethanol over Pd–Cu supported on Cu porphyrin (TPPCu) was investigated. The catalyst was synthesized using the microwave-assisted polyol method and physicochemically characterized by XRD, XPS, SEM, EDS, TEM, EDAX, UV–Vis, FTIR, and RBS. A Cu-enriched catalyst with Cu3Pd, Pd,Cu, and TPPCu phases was identified using XRD and XPS. However, according to the RBS results, the catalytic surface was enriched with Pd, indicating that the interaction between TPPCu and Pd–Cu allowed the presence of Pd on the surface, thus enhancing the catalytic response of the material. This synthesis prevented the deprotonation of porphyrin on the electrocatalyst, as confirmed by XPS analysis. Electrochemical studies based on cyclic voltammetry and electrochemical impedance spectroscopy were used to investigate the response of the catalyst to variations in the scan rate and increasing ethanol concentration. The electrochemical response of PdCu/TPPCu improved with an increasing number of cycles, indicating improved mass transport, thus improving its electrochemical response and tolerance to CO contamination. This catalyst exhibited a high electroactive surface area of 49.4 m2/g, which could be related to the presence of TPPCu as a support. The behavior of the catalyst on the anode of a fuel cell fed with ethanol, bioethanol, and bioethanol residues was evaluated. [ABSTRACT FROM AUTHOR]

Oxidative stress (OS) and endoplasmic reticulum stress (ERS) are at the genesis of placental disorders observed in preeclampsia, intrauterine growth restriction, and maternal hypothyroidism. In this regard, cationic manganese porphyrins (MnPs) comprise potent redox-active therapeutics of high antioxidant and anti-inflammatory potential, which have not been evaluated in metabolic gestational diseases yet. This study evaluated the therapeutic potential of two MnPs, [MnTE-2-PyP]5+ (MnP I) and [MnT(5-Br-3-E-Py)P]5+ (MnP II), in the fetal-placental dysfunction of hypothyroid rats. Hypothyroidism was induced by administration of 6-Propyl-2-thiouracil (PTU) and treatment with MnPs I and II 0.1 mg/kg/day started on the 8th day of gestation (DG). The fetal and placental development, and protein and/or mRNA expression of antioxidant mediators (SOD1, CAT, GPx1), hypoxia (HIF1α), oxidative damage (8-OHdG, MDA), ERS (GRP78 and CHOP), immunological (TNFα, IL-6, IL-10, IL-1β, IL-18, NLRP3, Caspase1, Gasdermin D) and angiogenic (VEGF) were evaluated in the placenta and decidua on the 18th DG using immunohistochemistry and qPCR. ROS and peroxynitrite (PRX) were quantified by fluorometric assay, while enzyme activities of SOD, GST, and catalase were evaluated by colorimetric assay. MnPs I and II increased fetal body mass in hypothyroid rats, and MnP I increased fetal organ mass. MnPs restored the junctional zone morphology in hypothyroid rats and increased placental vascularization. MnPs blocked the increase of OS and ERS mediators caused by hypothyroidism, showing similar levels of expression of HIFα, 8-OHdG, MDA, Gpx1, GRP78, and Chop to the control. Moreover, MnPs I and/or II increased the protein expression of SOD1, Cat, and GPx1 and restored the expression of IL10, Nlrp3, and Caspase1 in the decidua and/or placenta. However, MnPs did not restore the low placental enzyme activity of SOD, CAT, and GST caused by hypothyroidism, while increased the decidual and placental protein expression of TNFα. The results show that treatment with MnPs improves the fetal-placental development and the placental inflammatory state of hypothyroid rats and protects against oxidative stress and reticular stress caused by hypothyroidism at the maternal-fetal interface.

Antibiotic resistance represents a pressing global health challenge, now acknowledged as a critical concern within the framework of One Health. Photodynamic inactivation of microorganisms (PDI) offers an attractive, non-invasive approach known for its flexibility, independence from microbial resistance patterns, broad-spectrum efficacy, and minimal risk of inducing resistance. Various photosensitizers, including porphyrin derivatives have been explored for pathogen eradication. In this context, we present the synthesis, spectroscopic and photophysical characteristics as well as antimicrobial properties of a palladium(II)-porphyrin derivative (PdF2POH), along with its zinc(II)- and free-base counterparts (ZnF2POH and F2POH, respectively). Our findings reveal that the palladium(II)-porphyrin complex can be classified as an excellent generator of reactive oxygen species (ROS), encompassing both singlet oxygen (Φ△ = 0.93) and oxygen-centered radicals. The ability of photosensitizers to generate ROS was assessed using a variety of direct (luminescence measurements) and indirect techniques, including specific fluorescent probes both in solution and in microorganisms during the PDI procedure. We investigated the PDI efficacy of F2POH, ZnF2POH, and PdF2POH against both Gram-negative and Gram-positive bacteria. All tested compounds proved high activity against Gram-positive species, with PdF2POH exhibiting superior efficacy, leading to up to a 6-log reduction in S. aureus viability. Notably, PdF2POH-mediated PDI displayed remarkable effectiveness against S. aureus biofilm, a challenging target due to its complex structure and increased resistance to conventional treatments. Furthermore, our results show that PDI with PdF2POH is more selective for bacterial than for mammalian cells, particularly at lower light doses (up to 5 J/cm2 of blue light illumination). This enhanced efficacy of PdF2POH-mediated PDI as compared to ZnF2POH and F2POH can be attributed to more pronounced ROS generation by palladium derivative via both types of photochemical mechanisms (high yields of singlet oxygen generation as well as oxygen-centered radicals). Additionally, PDI proved effective in eliminating bacteria within S. aureus-infected human keratinocytes, inhibiting infection progression while preserving the viability and integrity of infected HaCaT cells. These findings underscore the potential of metalloporphyrins, particularly the Pd(II)-porphyrin complex, as promising photosensitizers for PDI in various bacterial infections, warranting further investigation in advanced infection models. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel MTCPPOMe/P-Mn x Cd 1-x S photocatalyst was designed and synthesized. • Pure water was decomposed to produce hydrogen without using sacrificial reagents. • Charge density difference calculation showed photoelectrons transfer direction. Photocatalytic water splitting over semiconductors is an important approach to solve the energy demand of human beings. Most photocatalytic H 2 generation reactions are conducted in the presence of sacrificial agent. However, the use of sacrificial reagents increases the cost of hydrogen generation. Realizing photocatalytic water splitting for hydrogen production without the addition of sacrificial agents is a major challenge for photocatalysts. The porphyrin MTCPPOMe and P doped Mn x Cd 1-x S make a significant contribution in facilitating the Mn x Cd 1-x S photocatalytic pure water splitting to H 2 reaction. Herein, a novel MTCPPOMe/P-Mn x Cd 1-x S (M = 2H, Fe, Co, Ni) composite catalyst which can efficiently split pure water without using sacrificial agents is developed. As a result, the H 2 generation rate of CoTCPPOMe/P-Mn 0.5 Cd 0.5 S is as high as 2.10 μmol h−1, which is 9.1 and 4.2 times higher than that of Mn 0.5 Cd 0.5 S (MCS) and P-Mn 0.5 Cd 0.5 S (P-MCS), respectively. P doped Mn x Cd 1-x S inhibits the recombination of photogenerated carriers, and introduction of MTCPPOMe as co-catalyst enhances the reduction capacity. In summary, an efficient and economical photocatalystis prepared for pure water splitting to prepare hydrogen. [ABSTRACT FROM AUTHOR]

Rice husk (RH) is one of the most abundant biomass having a unique natural structure. Herein, the highly porous rice husk carbon material (RHC) has been prepared. After loading metal (Fe, Co, Mn, Cu) complex of tetra-phenylporphyrin (TPP) and the followed calcination, a new kind of metal-nitrogen-carbon (M-N-C) electrocatalyst (MTPP/RHC) for the oxygen reduction reaction (ORR) was obtained. It was found that all prepared catalysts showed good ORR performance and the activity follows an order of Fe > Co > Mn > Cu catalyst. The best FeTPP/RHC catalyst exhibited an ORR activity with a half-wave potential of 0.88 V (E onset = 0.96 V) and excellent long-term stability (97% retention after 30000s). In the constructed zinc-air battery, it even showed a higher specific capacity (766 mAh/g) and superior reversibility than commercial Pt/C catalysts. This work provides a new practical protocol for ORR electrocatalysts. [Display omitted] • Porous biomass carbon material RHC have been obtained from rice husk. • Metalloporphyrin MTPP doped RHC M − N 4 catalyst FeTPP/RHC show good electrocatalytic oxygen reduction reaction activity. • E 1/2 of FeTPP/RHC in oxygen reduction reaction is superior than most of the reported biomass-carbon catalysts. • The FeTPP/RHC Zn-air batteries even exhibits higher specific capacity and reversibility than that of Pt/C catalyst. [ABSTRACT FROM AUTHOR]

Cuprous(I) catalysts have been widely used in the coupling reaction of forming C‐X bond. The core‐modified porphyrins are known to stabilize the unusual oxidation state of many metals. Thus, in this work, a 21‐oxaporphyrin was obtained under the improved Adler–Longo condensation condition and successfully used for complexing the cuprous ion. It is found that the synergy of the two factors, the diameter expansion and the univalent form of the N₃O core in the ligand, plays a decisive role in stabilizing the metastable ion; the former effectively stabilizes the electron pair of the equatorial d orbital by aiding the d‐π interaction, and the latter exactly balances the single charge of the ion. A size axis of copper species in porphyrinate systems is established by comparing with two previously reported distorted copper(II) porphyrin series. [ABSTRACT FROM AUTHOR]

Developing robust oxygen reduction reaction (ORR) electrocatalysts with high activity and durability remains great challenging while noble metal aerogels (NMAs) hold great potential because of their hierarchically porous morphology, excellent activity, and self‐supported characteristic. Herein, a general molecular engineering strategy to synthesize molecule‐noble metal aerogels (M‐NMAs) via 3D assembly of metal nanoparticles (e.g., Pt, Pd, Au, Ag, and PtPd NPs) induced by metalloporphyrin as cross‐linkers is reported. Due to the well synergy of NMAs and porphyrin molecule in creating the facile reaction pathway for ORR catalysis, these M‐NMAs demonstrate boosted ORR activity and durability in different electrolytes. Particularly, the best PtPd‐based M‐NMA delivers 1.47 A mgPt−1 and 2.13 mA cm−2 in mass and specific activities, which are 11.3 and 14.2 times higher than those of the commercial Pt/C catalyst, respectively. Thus, this work not only provides a simple and universal functional engineering approach of NMAs with catalytic molecules, but also opens an avenue of the rational design for superior ORR electrocatalysts. [ABSTRACT FROM AUTHOR]

A series of mono‐functionalized aromatic 22π telluradithiasapphyrins containing functional groups such as p‐bromophenyl, p‐iodophenyl, p‐nitrophenyl and p‐trimethylsilylethynyl phenyl groups at one of the meso‐positions were synthesized by condensing appropriately functionalized unsymmetrical bithiophene diol and 16‐telluratripyrrane in CH2Cl2 under acid‐catalyzed conditions. To demonstrate the reactivity of mono‐functionalized telluradithiasapphyrins, we synthesized the first examples of covalently linked diphenyl ethyne bridged four novel 18π porphyrin/metalloporphrin‐22π telluradithiasapphyrin dyads by coupling meso‐ethynyl phenyl porphyrin with telluradithiasapphyrin containing meso‐iodophenyl group under Pd(0) coupling conditions followed by metalation of porphyrin unit by treating free base dyad with appropriate metal salts. The dyads were characterized and studied by mass, 1D & 2D NMR, absorption, cyclic voltammetry, fluorescence and DFT techniques. The DFT analysis showed that the porphyrin/metalloporphyrin and sapphyrin units in dyads orient with each other in different angles and Zn(II) porphyrin‐sapphyrin dyad (Zn‐dyad) showed minimum whereas the free base dyad showed maximum angle of deviation. NMR, absorption, and redox studies indicated that the dyads exhibit the overlapping features of their constituted monomers and maintain their individual characteristic features. The steady‐state fluorescence studies revealed that the fluorescence of the porphyrin/metalloporphyrin unit was significantly quenched due to possible energy/electron transfer from the porphyrin/metalloporphyrin unit to non‐emissive sapphyrin unit in dyads. [ABSTRACT FROM AUTHOR]

Two porphyrins, named H2TEtImP and H2DEtImP, with the four and two N‐ethylated imidazole groups, respectively, as well as their metalloporphyrins, M‐TEtImP (M = Zn, Mn, Co, Mg) and Zn‐DEtImP, were synthesized and characterized by ultraviolet–visible (UV–Vis), mass spectrometry (MS), proton nuclear magnetic resonance (1H NMR), and Fourier transform infrared (FTIR) successfully. The catalytic activity of these newly synthesized porphyrins with metal centers and halogen ions as variables on the cycloaddition reaction between carbon dioxide (CO2) and epoxides was investigated under solvent‐free conditions. The experimental results strongly verified that both halogen ions and metal centers were indispensable active sites. The metal catalytic activity increased in the order Co < Mn < Mg < Zn. The turnover frequency (TOF) of Zn‐TEtImP for the cycloaddition reaction of CO2 and epichlorohydrin was as high as 2213 h−1 (120°C, 1 MPa CO2, 6 h). Moreover, the wide applicability of Zn‐TEtImP to this reaction was demonstrated by substrate extension experiments, and the excellent recyclability of Zn‐TEtImP was confirmed. Finally, the synergistic catalytic mechanism of Lewis acid (metal center) and nucleophile (Br−) was proposed based on the catalytic results. [ABSTRACT FROM AUTHOR]

Coordination of metal ions by the tetrapyrrolic macrocyclic ring of porphyrin-based photosensitizers (PSs) affects their photophysical properties and consequently, their photodynamic activity. Diamagnetic metals increase the singlet oxygen quantum yield while paramagnetic metals have the opposite effect. Since singlet oxygen is considered the main cell-damaging species in photodynamic therapy (PDT), the nature of the chelated cation would directly affect PDT efficacy. This expectation, however, is not always supported by experimental results and numerous exceptions have been reported. Understanding the effect of the chelated metal is hindered because different chelators were used. The aim of this work was to investigate the effect of the nature of chelated cation on the photophysical and photodynamic properties of metalloporphyrins, using the same tetrapyrrole core as a chelator of Ag(II), Cu(II), Fe(III), In(III), Mn(III), or Zn(II). Results demonstrated that with the exception of Ag(II), all paramagnetic metalloporphyrins were inefficient as generators of singlet oxygen and did not act as PSs. In contrast, the coordination of diamagnetic ions produced highly efficient PSs. The unexpected photodynamic activity of the Ag(II)-containing porphyrin was attributed to reduction of the chelated Ag(II) to Ag(I) or to demetallation of the complex, caused by cellular reductants and/or by exposure to light. Our results indicate that in biological systems, where PSs localize to various organelles and are subjected to the action of enzymes, reactive metabolites, and reducing or oxidizing agents, their physicochemical and photosensitizing properties change. Consequently, the photophysical properties alone cannot predict the anticancer efficacy of a PS. [ABSTRACT FROM AUTHOR]

A room temperature and solvent‐free β‐chlorination and β‐bromination protocol for meso‐tetraarylporphyrinato nickel(II) complexes to access the β‐octahalogenated derivatives by ball‐milling is communicated. Various ball‐milling parameters were systematically studied. [ABSTRACT FROM AUTHOR]

Traditionally chemical modifications altering molecular skeletons (MSs) were the only solution to modulate material active sites at ground states. According to Runge–Gross theorem, the MS and the adjoint electron‐configuration (MS‐AEC) can be tuned at excited states (ESs), even without chemical modifications. A porphyrinic metal–organic framework PCN‐222 and its metalloporphyrin homologs are used for adsorptive carbon capture both at ground states and with photoexcitation (350–780 nm). Instead of passive photothermal effects, the carbon capture performances of all the adsorbents get promotions. The dominant first ESs with long lifetimes meet the time‐scale of molecular adsorption equilibrium, meanwhile tune the MS‐AEC of the porphyrin ligands to generate new active sites with much more negative electrostatic‐potentials, of which the distribution gradient is crucial for inducing CO2 and can be further modulated by the central‐coordinated metal cations at ground and excited states. This work demonstrates the availability of static ESs and possibility of nonchemical modifications. [ABSTRACT FROM AUTHOR]

Due to the synergistic effect of central metal and halide anion, cationic metalloporphyrins and derivatives exhibit outstanding catalytic activities for the cycloaddition reaction of epoxides and carbon dioxide. Herein, a generic strategy was developed to synthesize the benzimidazolium‐containing metalloporphyrin molecule and polymer. To demonstrate the method feasibility, we firstly synthesized the molecule 1H, in which the benzimidazole groups were in‐site constructed by the cyclization of 5,10,15,20‐(4‐carboxyphenyl)‐porphyrin (H2TCPP) with o‐diaminobenzene (PEA). After post‐synthetic ionization and metallization, I− and Zn2+ were introduced as the nucleophile and Lewis acid, respectively. The structure of 1ZnIL was confirmed by single crystal X‐ray diffraction analysis. By using the similar conditions of model reaction, H2TCPP was copolymerized with 1,2,4,5‐tetraaminobenzene (BTA) to prepare the polymer P‐1ZnIL. The prepared cationic molecule 1ZnIL and polymer P‐1ZnIL showed comparable activities in catalyzing the cycloaddition of carbon dioxide with epoxides to cyclic carbonates compared to the reported bifunctional catalysts based on metalloporphyrins. [ABSTRACT FROM AUTHOR]

The quantitative structure–electrochemistry relationship (QSER) method was applied to a series of transition-metal-coordinated porphyrins to relate their structural properties to their electrochemical CO2 reduction activity. Since the reactions mainly occur within the core of the metalloporphyrin catalysts, the cluster model was used to calculate their structural and electronic properties using density functional theory with the M06L exchange–correlation functional. Three dependent variables were employed in this work: the Gibbs free energies of H*, C*OOH, and O*CHO. QSER, with the genetic algorithm combined with multiple linear regression (GA–MLR), was used to manipulate the mathematical models of all three Gibbs free energies. The obtained statistical values resulted in a good predictive ability (R2 value) greater than 0.945. Based on our QSER models, both the electronic properties (charges of the metal and porphyrin) and the structural properties (bond lengths between the metal center and the nitrogen atoms of the porphyrin) play a significant role in the three Gibbs free energies. This finding was further applied to estimate the CO2 reduction activities of the metal–monoamino–porphyrins, which will prove beneficial in further experimental developments. [ABSTRACT FROM AUTHOR]

Hypercrosslinked polymers (HCPs) constructed by Friedel‐Crafts reaction have drawn increasing attention in recent decades, but their multifunctionalization remains a huge challenge. Herein, a series of aluminum‐porphyrin‐based hypercrosslinked ionic polymers have been successfully synthesized by direct knitting approach without additional electrophilic comonomers, which involves the copolymerization of neutral porphyrin monomers and ionic building. By increasing the connected nodes numbers of ionic monomers, the introduction of abundant tetraphenylmethane fragements into the porphyrin backbones endows them with high‐density ionic active sites. Accordingly, the well‐matched molar ratios of aluminum sites to nucleophilic chloride anions that work synergistically for CO2/epoxide coupling can be achieved. Al‐HIP‐2 with flexible ionic pendants and a high Al/Cl ratio allows CO2 cycloaddition to be performed at ambient conditions or with diluted CO2; while Al‐HIP‐3 with rigid ionic moieties and a relatively low Al/Cl ratio exhibits higher specific surface area and stronger CO2 capture ability. Therefore, this co‐condensation strategy provides a simple and feasible pathway for adjusting the reactivity ratios of comonomers via simple structural changes in the knitting process, thus achieving the rational construction of multifunctionalized HCPs for CO2 capture and in‐situ conversion to cyclic carbonates. [ABSTRACT FROM AUTHOR]

Porphyrin derivatives represent an emerging class of redox‐active materials for sustainable electrochemical energy storage. However, their structure–performance relationship is poorly understood, which confines their rational design and thus limits access to their full potential. To gain such understanding, we here focus on the role of the metal ion within porphyrin molecules. The A2B2‐type porphyrin 5,15‐bis(ethynyl)‐10,20‐diphenylporphyrin and its first‐row transition metal complexes from Co to Zn are used as models to investigate the relationships between structure and electrochemical performance. It turned out that the choice of central metal atom has a profound influence on the practical voltage window and discharge capacity. The results of DFT calculations suggest that the choice of central metal atom triggers the degree of planarity of the porphyrin. Single crystal diffraction studies illustrate the consequences on the intramolecular rearrangement and packing of metalloporphyrins. Besides the direct effect of the metal choice on the undesired solubility, efficient packing and crystallinity are found to dictate the rate capability and the ion diffusion along with the porosity. Such findings open up a vast space of compositions and morphologies to accelerate the practical application of resource‐friendly cathode materials to satisfy the rapidly increasing need for efficient electrical energy storage. [ABSTRACT FROM AUTHOR]

Heterogenized metalloporphyrin catalysts for oxidation reactions are extensively explored to improve chemical production. In this work, manganese meso-tetraarylporphyrins were immobilized on hydrated mesoporous titanium dioxide (SBET = 705 m2 g−1) through carboxylate or phosphonate anchoring groups separated from the macrocycle by the 2-arylimidazole linker fused across one of the pyrrolic rings of the macrocycle. The element composition of two mesoporous hybrid materials thus obtained were investigated and the integrity of the immobilized complexes was shown by different physicochemical methods. Finally, the catalytic efficiency of the more stable material Mn(TMPIP)/TiO2 with the phosphonate anchor was evaluated in the selective oxidation of sulfides to sulfoxides by molecular oxygen in the presence of isobutyraldehyde (IBA). The heterogenized complex has shown excellent catalytic activity exhibiting a turnover (TON) of ~1100 in a single catalytic run of the sulfoxidation of thioanisole. The catalyst was successfully reused in seven consecutive catalytic cycles. [ABSTRACT FROM AUTHOR]

The application of metalloporphyrin in the field of catalysis is one of the hotspots currently by the domestic and foreign scholars. The chemists have been able to successfully mimic several types of oxidation reactions using metalloporphyrin as catalyst. At first, homogeneous system presents the most amenable strategy for oxidizing a vast array of substrates, for example, catalytic oxidation of small molecules, ring-opening polymerization of cyclic compounds and photo-induced electron transfer reversible addition-fragmentation chain transfer polymerization, etc. However, as homogeneous catalyst, metalloporphyrin has some limitations such as poor stability, easy deactivation, difficult separation, high cost and environmental concerns, which have directed research in this field to the design, synthesis, and applications of heterogeneous catalyst. Transforming metalloporphyrin into heterogeneous catalyst with stable chemical properties, excellent catalytic performances and special constructions have been the focus of research and practical application in the field of catalysis. Herein, in this review, we summarize the most important advances made by the scientific community in various catalytic applications and heterogeneous techniques of metalloporphyrin in the past ten years. We emphasize the applications of such catalysts on the oxidation reactions of many relevant substrates using homogeneous and heterogeneous metalloporphyrin-based catalyst, and we discuss the activity and stability of heterogeneous metalloporphyrin, as well as procedures. Moreover, the influences of flexible microenvironment formed by heterogeneous metalloporphyrin-based catalyst on the photo-catalytic behavior are discussed in this review. [ABSTRACT FROM AUTHOR]

While porphyrin-related syntheses have become classic experiments in the undergraduate curriculum, traditional syntheses of the free-base meso-tetraphenylporphyrin (H2TPP) and its metallated derivatives can be energy-intensive, use hazardous solvents, and generate appreciable amounts of waste. In an attempt to make the synthesis of H2TPP and its metallated derivatives (MTPP where M = metal) better aligned with the principles of green chemistry, we optimized a microwave-assisted, microscale synthesis of H2TPP and alternative routes toward the metallation of H2TPP including solvent-substituted reflux and mechanochemical syntheses for the undergraduate teaching laboratory. The greenness of these syntheses were evaluated using various green metrics and qualitative comparison to previously reported syntheses. [ABSTRACT FROM AUTHOR]

Introduction: Metalloporphyrin-based contrast agents can improve probe functionality such as biocompatibility, prolonging presence in blood, and specific tumor accumulation. Herein, we report synthesis, structural characteristics, quality control, and nuclear imaging of new metalloporphyrin-based contrast agents. Methods: To combine photodynamic therapy (PDT), magnetic resonance imaging (MRI), positron emission tomography (PET), and single-photon emission computerized tomography (SPECT), Gadolinium-proto porphyrin IX complex was synthesized via direct complexation method, then the metalloporphyrin (MP) was labeled with gallium-67 and gallium-68 in separated runs. In-vivo biodistribution studies were performed in mice bearing breast tumor (4T1 mouse mammary tumor cell line) and normal rats (for better visualization). Results: Adsorption of the labeled compound into the tumor (ID/g % up to 4.6%), despite the small size of the tumor, had an upward trend at all times, and high and fast (less than 45 min) uptake of radiotracer in cancerous tumors was observed. Conclusion: Fast and high tumor uptake revealed that this radiotracer could potentially be used as a theranostic agent. [ABSTRACT FROM AUTHOR]

ABSTRACTWhile porphyrin-related syntheses have become classic experiments in the undergraduate curriculum, traditional syntheses of the free-base meso-tetraphenylporphyrin (H2TPP) and its metallated derivatives can be energy-intensive, use hazardous solvents, and generate appreciable amounts of waste. In an attempt to make the synthesis of H2TPP and its metallated derivatives (MTPP where M = metal) better aligned with the principles of green chemistry, we optimized a microwave-assisted, microscale synthesis of H2TPP and alternative routes toward the metallation of H2TPP including solvent-substituted reflux and mechanochemical syntheses for the undergraduate teaching laboratory. The greenness of these syntheses were evaluated using various green metrics and qualitative comparison to previously reported syntheses.

Hemin/CNT/Ti 3 C 2 T x hybrid with redox catalytic ability for electrochemical determination of H 2 O 2 and UA. [Display omitted] Herein, a functional hybrid named metalloporphyrin hemin modified carbon nanotube decorated titanium carbide (Hemin/CNT/Ti 3 C 2 T x) with redox catalytic ability is studied and applied to electrochemical sensing. The morphology, crystal structure and chemical composition of the hybrid are investigated through field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET) analysis. Benefiting from the unique multilayer structure, strong enrichment ability, excellent electrochemical performance of CNT/Ti 3 C 2 T x and outstanding catalytic property of hemin, the developed Hemin/CNT/Ti 3 C 2 T x hybrid presents desirable performance for electrochemical sensing. Two independent electrochemical sensing techniques including chronoamperometry (i-t) and differential pulse voltammetry (DPV) are adopted to realize hydrogen peroxide (H 2 O 2) and uric acid (UA) determination, demonstrating the excellent redox catalytic ability of Hemin/CNT/Ti 3 C 2 T x. More importantly, it is successfully applied to real-time monitoring of H 2 O 2 released from living cells, and accurate determination of UA in urine samples is also realized, demonstrating a good practicability. [ABSTRACT FROM AUTHOR]

Porphyrins have a large π–π conjugation force between molecules, and they are easy to aggregate in solution, which affects the photoelectric properties of porphyrins. Connecting porphyrins to polymer links through covalent bonds not only retains the mechanical properties and thermal stability of polymer materials, but also has the photoelectric properties and catalytic properties of porphyrins, which improves the availability of materials. In this study, first, a porphyrin ligand with double bonds in the side chain was designed and the corresponding copper and zinc complexes were synthesized by adjusting the metal ions in the center of the pyrrole ring. Then, the metalloporphyrin complexes were copolymerized with methyl methacrylate (MMA), and two metalloporphyrin/PMMA copolymers were obtained: CPTPPCu/PMMA and CPTPPZn/PMMA. The structure of the compounds was characterized by IR, 1H NMR, MS, and UV-Vis spectra. Metalloporphyrin/PMMA copolymers were prepared into electrospun fiber materials by electrospinning. The morphology of the composites was studied by SEM, and the thermal stability and optical properties of electrospun fibers were studied by TGA and FL. The catalytic activity of electrospun fiber materials for the degradation of organic dyes was studied. The results showed that the efficiency of the metalloporphyrin/PMMA copolymer in photocatalytic degradation of methylene blue (MB) was better than that of the PMMA electrospun fiber blended with metalloporphyrin. [ABSTRACT FROM AUTHOR]

Inspired by the ligand‐promoted high reactivity of the heme active center in cytochrome c oxidase (CcO) toward oxygen reduction reaction (ORR), this work proposes a new strategy for improving the efficiency of metalloporphyrin‐catalyzed ORR. We carried out a comparative study between two graphene/cobalt porphyrin complexes, the rGO/TMPPCo formed by noncovalent π‐π stacking, and the rGO‐Ci/TMPPCo with cobalt porphyrins (TMPPCo) axially coordinated with the 1‐carboimidazole (Ci) ligands on reduced graphene oxide (rGO) surface. The involvement of the axial ligand was found to greatly reduce the ORR overpotential by 120 mV in acidic medium, while hydrodynamic tests revealed an unaltered reaction mechanism. This positive effect of axial ligand has been rationalized by both electronic "push effect" and steric "trans effect". The results of this work highlight the importance of a rationally engineered electronic structure of active sites in heterogeneous catalysis, providing insights for the fabrication of highly‐efficient ORR electrocatalysts. [ABSTRACT FROM AUTHOR]

In this study, the 5,10,15,20-tetrakis-(4-hydroxyphenyl)porphyrin (TpOHPP) and its Zn, Cu, and Co complexes have been synthesized and evaluated as photosensitizers and for anti-inflammatory activity. TpOHPP and its Zn (Zn-TpOHPP), Cu (Cu-TpOHPP), and Co (Co-TpOHPP) ligands have been synthesized using the Alder-Longo method; their photosensitizer activity has been screened by irradiating HeLa cells with red light, comparing their relative activity to those of protoporphyrin IX (PpIX) and cisplatin (CDDP). The edema mouse model in which inflammation is induced with 12-O-tetradecanoylphorbol 13-acetate (TPA) has been adopted. Finally, molecular modeling (docking) on the test drugs have been conducted using the Autodock VINA software. TpOHPP induced time-dependent cell replication inhibition when the cells are exposed to red light (IC50 = 16.35 µM, 2.3 µM, and 2.1 µM at 0, 15, and 30 minutes, respectively). Comparatively, Zn-TpOHPP exerts essentially the same cell replication inhibitory profile with and without red light exposure (IC50 = 1.35 µM and 1.38 µM respectively). The percent inhibition of inflammation determined for the test molecules are 54.16% for TpOHPP, 60.38% for Zn-TpOHPP, 67.10% for Cu-TpOHPP, and 67.53% with Co-TpOHPP. TpOHPP and its Zn complex show anti-proliferative activity at low micromolar levels and the four porphyrins exerted significant anti-inflammatory activity in vivo. [ABSTRACT FROM AUTHOR]

Porphyrins are selected as building units to synthesize porphyrin‐based covalent organic polymers (COPs), which can combine the excellent properties of covalent organic polymers with the fantastic catalytic effect of porphyrin to obtain a heterogeneous catalyst with excellent catalytic activity. In this work, the novel benzimidazole‐linked porphyrin COPs MPp‐BTA (M = 2H, Zn, Co) were synthesized using a new porphyrin with aldehyde group peripherally MPp (M = 2H, Zn, Co) and 1,2,4,5‐tetraminobenzene tetrahydrochloride (BTA) as monomers. The synthesized MPp‐BTA were carefully characterized by FT‐IR, UV–vis, SEM, TEM, TG, and PXRD. As heterogeneous catalyst, MPp‐BTA (M = Zn, Co) shows the high catalytic activity and stability for cycloaddition of CO2 with phenyl glycidyl ether (PGE) under mild conditions (80°C, 0.1 MPa CO2), and the yield of cyclocarbonate can reach 95% and 92% respectively. In addition, the recycling stability of ZnPp‐BTA was investigated, and the yield of cyclocarbonate was still remained at 86% after five cycles. Furthermore, MPp‐BTA (M = 2H, Zn, Co) can be used directly as heterogeneous photocatalysts for selective oxidation of thioanisole to methyl phenyl sulfoxide. To our delight, H2Pp‐BTA shows satisfactory photocatalytic performance, and the yield of methyl phenyl sulfoxide can reach 93% in 4 h. [ABSTRACT FROM AUTHOR]

Covalent linking of 5,10,15,20 meso tetra(4-aminophenyl) porphyrin (TAP) and its zinc complex with single-walled carbon nanotubes (SWCNTs) (nanohybrids A and B, respectively) has been reported. Significant decrease in the intensity of D-band and higher frequency shift of G-band of SWCNT-TAP in Raman spectrum reveals the improved graphitic sp2 hybridization of SWCNT as compared to SWCNT-ZnTAP. This is due to the functionalization of free base porphyrin (electron donating group) in the nanohybrid A. Shifting of carbonyl stretching frequency from 1700 cm−1 to 1680 cm−1 and further appearance of striking bands in the X-ray photoelectron spectroscopy (XPS) and FTIR spectra of nanohybrids A and B confirm the covalent linking of porphyrin chromophores with SWCNTs. XPS reveals that the extent of functionalization of nanohybrid A is more as compared to nanohybrid B. These nanohybrids demonstrate positive solvatochromism. Upon excitation at 450 nm, the nanohybrids A and B reveal ∼76% and 65% fluorescent quenching of emission bands at 686 and 632 nm, respectively. This is due to the energy or electron transfer from porphyrins to SWCNTs. [ABSTRACT FROM AUTHOR]

Caffeic acid is an antioxidant that has been widely been related to the health benefits of people in recent years. In this paper, the amino side chains of chitosan (CS) were modified with protoporphyrin IX by amide cross-linking, and then Zn ions were chelated. The properties of metalloporphyrin-preparing functionalized multi-walled carbon nanotubes (MWCNTs) and Zn ions chelated by protoporphyrin IX composites were used as sensitive-selective electrochemical biosensors for the determination of caffeic acid. The morphology and structure of nanocomposite Zn–PPIX–CS–MWCNTs were observed by X-ray spectroscopy mapping (EDX mapping), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FTIR). The electrochemical behaviors of Zn–PPIX–CS–MWCNT-modified glassy carbon (GC) electrodes were evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results show that the modified electrode had good electrocatalytic activity towards caffeic acid with a wide linear range of 0.0008–1.6 mM, an excellent sensitivity of 886.90 µAmM−1cm−1, and a detection limit of 0.022 µM. In addition, the caffeic acid sensor had excellent reproducibility, stability, and selectivity to various interfering substances. Therefore, the modified electrode prepared by this experiment can also be applied to electrochemical sensors of other substances. [ABSTRACT FROM AUTHOR]

Abstract In this study, the sensing characteristics of tin oxide-based gas sensors deposit with different amounts of metalloporphyrin, which is a functionalization substance, are evaluated. The mass of metalloporphyrin deposited is 3, 10, 20, 30, and 40 mg for 5 different sensors prepared. The deposition of 3 mg of metalloporphyrin result in an island form of functionalization instead of a thin film; meanwhile, thin films with thicknesses of 25, 35, 74, and 92 nm are formed for the other four cases. As the deposition amount of metalloporphyrin increase, the performance of the sensor deteriorate. The samples are prepared by subdividing the amount of metalloporphyrin source to determine the optimized deposition amount. A sample is prepared with deposition amounts ranging between 1 to 10 mg. The sensors deposit with 3–5 mg metalloporphyrin has excellent response, response, and recovery time characteristics.

• The M-NC catalysts (M = Co, Cu, Ni and Zn) are prepared by a simple method. • The catalytic precursors are UiO-66-NH 2 doped with non-noble metal porphyrins. • The Co-NC catalyst shows excellent HER properties under acidic and alkaline conditions. This study adopts non-noble metal porphyrin-doped UiO-66-NH 2 as a precursor to form highly dispersed metal active species embedded into graphite-like carbon-based materials (metal = Co, Cu, Ni, and Zn) through high-temperature pyrolysis for electrocatalytic hydrogen evolution (HER). The metalloporphyrin provides anchoring sites to facilitate the stabilization of metal species, while the graphite-like carbon-based materials formed derived from metal-organic framework (MOFs) precursor pyrolysis could enhance the transport of electrons. Electrochemical studies indicate that Co-NC has the best performance among the four non-noble metal carbon materials. When the current density is 10 mA·cm−1, the overpotentials of Co-NC in acidic and alkaline media are 256 mv and 325 mv, respectively, and the Tafel slopes are 162.46 mV·dec−1 and 143.05 mV·dec−1, respectively. Therefore, the pyrolysis of MOFs precursor incorporated with a certain amount of metalloporphyrin to form graphite-like carbon-based materials is an effective strategy to obtain low-cost, stable HER catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • The feasibility of employing Pt-TPP as a substitute for porphyrin in studying the singlet oxygen generation proportion from triplet state in water was explored and confirmed. • A first-order decay model of the excited triplet states for Pt-TPP was constructed and confirmed. • The total transition rate of the T 1 state (A 0) value under pure water content was predicted to be 0.021 μs−1. • Combined with A 0 and the quenching rate constant of T 1 by O 2 (k q), the formula for R in relation to changes in oxygen can be deduce. The proportion of singlet oxygen (R) produced from the triplet state of porphyrin in aqueous solutions was investigated by substituting porphyrin molecules with the metalloporphyrin Platinum(II) meso -tetraphenylporphyrin (Pt-TPP). The feasibility of using platinum porphyrin as a substitute for porphyrin to study the photophysical properties in photodynamic therapy (PDT) was confirmed. The model of first-order decay in a water-methanol mixed solution encompasses potential deactivation processes of the excited triplet states and was built, which was confirmed by monitoring the change in the total transition rate of the T 1 state (A 0) value at different water contents under anoxic environments, obtained through measuring the phosphorescence lifetime (τ p) of Pt-TPP. Combined with A 0 and the quenching rate constant of T 1 by O 2 (k q), the formula for R in relation to changes in oxygen can be deduced in pure water. [ABSTRACT FROM AUTHOR]

The electrocatalytic performance of Et@PZn and LPOM@EtPZn for HER and OER in alkaline media was systematically assessed. Notably, LPOM@EtPZn exhibited a lower overpotential for HER and OER than Et@PZn indicating its superior kinetics, which was further confirmed by Tafel slope values. So, LPOM@EtPZn showed enhanced catalytic efficiency than Et@PZn due to the incorporation of POM into a layer structure creating synergistic effects. [Display omitted] • In this article we have reported. • Et@PZn COF was synthesized from metalloporphyrin and ethylenediamine. • Lindqvist POM was incorporated into COF's cavities, resulting LPOM@EtPZn framework. • Et@PZn and LPOM@EtPZn were tested for HER and OER in an alkaline medium. • LPOM@EtPZn exhibited lower overpotential than Et@PZn indicating superior kinetics. An effective method for producing valuable fuels is electrocatalytic water dissociation, which involves the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). So, the development of new electrocatalysts for enhancing these processes is expected to minimize their overpotentials and increase the accessibility of their practical applications. The multifunctional properties of porphyrins and polyoxometalate (POMs) can help energy conversion devices. This study presents the synthesis of a novel metalloporphyrin and ethylenediamine-containing covalent organic framework (Et@PZn) and its successful incorporation of Lindqvist POM into the COF's cavities, resulting in the LPOM@EtPZn framework. Both frameworks underwent comprehensive structural and morphological characterizations. The electrocatalytic performance in alkaline media was systematically assessed. Notably, LPOM@EtPZn exhibited a lower overpotential for HER and OER than Et@PZn indicating its superior kinetics, which was further confirmed by Tafel slope values of about 115 mV dec−1 and 55 mV dec−1 for LPOM@EtPZn which found better than that of Et@PZn of about 161 mV dec−1 and 108 mV dec−1 for HER and OER respectively. LPOM@EtPZn also showed best overpotential than standard 20 %Pt/C electrode for HER. Electrochemical investigations, including electroactive surface area (ECSA) measurement and electrochemical impedance spectroscopy (EIS), also confirmed the charge transfer advantages of LPOM@EtPZn. These findings underscore the potential of LPOM@EtPZn as a versatile and efficient electrocatalyst for diverse applications, in advancing renewable energy technologies. [ABSTRACT FROM AUTHOR]

• Density functional theory calculations were conducted to screen metalloporphyrin catalysts (M-PORs) with varying peripheral ligands, metal centres, and oxidation states for the activation of CO 2. • The set of criteria used to shortlist M-PORs were based on the ability to lengthen and bend CO 2 , bind CO 2 , and donate charge from the metal centre to CO 2. • The selected set of M-POR predominantly exhibit the electron configuration of the metal centre in d[6] and d[7] configurations. • Natural bond orbital analysis revealed the impact of electron-withdrawing groups in the system, while electron-donating groups in the ligand structure enhance CO 2 activation. Electrocatalytic CO 2 reduction (eCO 2 R) to value-added chemicals offers a promising route for carbon capture and utilization. Metalloporphyrin (M-POR) is a class of catalysts for eCO 2 R that has drawn attention due to its tuneable electronic and structural properties. This work presents a computational screening, based on density functional theory calculations, of one of the key steps in the eCO 2 R: the adsorption of CO 2 on 110 M-PORs with varying peripheral ligands, metal centres, and oxidation states, to understand how these factors can influence CO 2 activation. A set of criteria was used to shortlist M-PORs based on their ability to lengthen the C–O bond, bend the O–C–O angle, bind CO 2 , and donate charge from the metal of the M-POR to the carbon of CO 2. 16 systems were selected for their potential to activate CO 2. These systems predominantly have the electron configuration of the metal centre in the d[6] and d[7] configurations. Natural bond orbital analysis revealed the impact of electron-withdrawing groups in the system, which increases orbital splitting and, consequently, lowers the ability of the M-POR to activate CO 2. Second-order perturbation theory analysis confirms that the presence of electron-donating groups in the ligand structure enhances CO 2 activation. This work demonstrates the interconnected effect of peripheral ligands, metal centres, and oxidation states in M-PORs on their ability to adsorb and activate CO 2 , thereby establishing structure-activity relationships within M-PORs. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent years, the development of efficient drug delivery systems has garnered significant attention to enhance the therapeutic efficacy and mitigate the adverse effects of anticancer drugs. Herein, we investigate the promising metalloporphyrin-like C 54 N 4 fullerene (TM-PC60F) nanoclusters as a novel drug delivery platform for 5-fluorouracil (5-Fu) using density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) analyses. We explore the structural stability, electronic properties, and binding interactions of TM-PC60F nanoclusters with 5-Fu molecules through comprehensive computational simulations. Our results unveil the favorable adsorption energy of 5-Fu molecules to TM-PC60F nanoclusters, suggesting their potential as carriers for drug delivery applications. Furthermore, DFT calculations elucidate the electronic structure and energetics of the 5-Fu@TM-PC60F complexes, shedding light on the mechanisms underlying their interaction. QTAIM analysis provides deeper insights into the nature of intermolecular interactions within the complexes, highlighting the presence of significant non-covalent interactions crucial for drug encapsulation and release. This study not only provides valuable theoretical insights into the feasibility of utilizing TM-PC60F nanoclusters as a drug delivery platform for 5-Fu but also paves the way for the design and development of advanced nanocarriers with enhanced drug delivery capabilities and therapeutic outcomes in cancer treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

Efficient and selective oxygenation of α-C-H bonds in alkyl aromatics with dioxygen was accomplished through heterogeneous catalysis in the confined reaction channels of metalloporphyrin-based 2D POFs with residual groups being capped. [Display omitted] • A novel and effective oxygenation model of C-H bonds in limited reaction channel. • Prevented over-oxidation in oxygenation of C-H with O 2 in limited reaction channel. • Increased selectivity in C-H bonds oxygenation by heterogeneous catalysis. • Oxygenation of C-H bonds with O 2 could be adapted by limited reaction channel. • Concurrently increased conversion and selectivity in C-H bonds oxygenation with O 2. Metalloporphyrin T(4-Br)PPCo was used in the construction of two-dimensional porous organic framework materials (2D POFs) in order to achieve the direct benzyl C-H bonds oxygenation. In order to prevent the disordered diffusion of free radicals in 2D POFs, a restricted reaction channel was constructed, and heterogeneous catalysis was applied to decrease the deep oxygenation of partial oxygenation products due to central metal sites. All 2D POFs were characterized as amorphous microporous materials containing highly and uniformly dispersed Co2+. It was used to partially oxygenate C-H bonds at benzyl position employing dioxygen in solvent-free condition, and the conversion and selectivity were improved at the same time, especially when residual -B(OH) 2 and -Br were capped. Compared with T(4-Br)PPCo, the substrate conversion increased from 39 % to 66 %, and the selectivity for 4-nitroacetophenone increased from 66 % to 91 %. The reaction mechanism, apparent kinetics and substrate compatibility were also studied. In this work, it provided a guiding reference for the effective C-H bonds oxygenation and other free radical based chemical reactions. The use of POFs in catalytic chemistry was further broadened, and a successful method for improving the catalytic characteristics of POFs by capping the remaining active groups was suggested. [ABSTRACT FROM AUTHOR]

Herein, we report a facile one-pot in situ self-assembly approach that enables a porphyrin photosensitizer, [5,10,15,20-tetrakis(4-methoxycarbonylphenyl)porphyrin]-Zn(II) (ZnTPP), to be enshrouded by a zeolitic imidazolate framework-8 (ZIF-8) to afford a novel visible-light-driven heterogeneous photosensitizer, ZnTPP@ZIF-8 composite. The ZnTTP photosensitizer was well dispersed and fully confined within the ZIF-8 crystals and the framework intactness and porosity were well maintained. The as-prepared ZnTPP@ZIF-8 composite integrates the advantages of ZIF-8 MOFs and ZnTTP photosensitizer. It not only can effectively produce both singlet oxygen (1O 2) and superoxide ion ( ∙ O 2 −) under visible light irradiation, but also exhibit high surface area and excellent stability. The structure characterization of ZnTPP@ZIF-8 composite was first carried out, and then this material can be used as a heterogeneous photosensitizer for the rapid and highly selective detoxification of a sulfur mustard simulant (2-chloroethyl ethyl sulfide) into the corresponding much less toxic sulfoxide product with a half-life of only 1.5 min under visible light irradiation at room temperature in air atmosphere. This catalyst can be readily recycled and reused at least six times without obvious loss of catalytic activity. This study will provide us a new strategy for the facile, rapid and environmentally friendly preparation of photosensitizer@MOFs composites and the rapid detoxification of sulfur mustard under ambient conditions in the future. A novel visible-light-driven heterogeneous photosensitizer, ZnTPP@ZIF-8 composite，has been designed and synthesized through a facile one-pot in situ self-assembly approach. Then this composite was successfully applied in detoxification of a sulfur mustard simulant (2-chloroethyl ethyl sulfide) into the corresponding much less toxic sulfoxide product. [Display omitted] • A facile one-pot in situ self-assembly approach to afford a novel visible-light-driven heterogeneous photosensitizer (ZnTPP@ZIF-8) was reported. • The preparation process of the ZnTPP@ZIF-8 composite is simple, mild and environmentally friendly. • The ZnTPP@ZIF-8 composite for the efficient detoxification of a sulfur mustard simulant in air was studied. • The ZnTPP@ZIF-8 composite exhibits high photocatalytic efficiency and selectivity in the oxidation of CEES, and excellent reusability. [ABSTRACT FROM AUTHOR]

Ultrathin two‐dimensional metal–organic framework nanosheets have emerged as a promising kind of heterogeneous catalysts. Herein, we report a series of 2D porphyrinic metal–organic framework nanosheets (X‐PMOF, X=F, Cl, Br), which was prepared from the self‐assembly of a halogen‐based porphyrin ligand X‐TCPP (X‐TCPP=5‐(4‐halogenatedphenyl)‐10,15,20‐tris(4‐carboxyphenyl)‐porphyrin) and ZrCl4 in the presence of trifluoroacetic acid as the modulating reagent. The framework of X‐PMOF possessed the ftw topology as in MOF‐525. The lamellar X‐PMOF nanosheets with the thickness of down to 4.5 nm were assembled and aggregated into a flower‐like morphology. With the introduction of iridium(III) atoms into the porphyrin rings, the resultant X‐PMOF(Ir) nanosheets were prepared by a similar method. Catalytic results show that Br‐PMOF(Ir) nanosheets were efficient for CO2 reduction and aminolysis, giving rise to formamides in high yields under room temperature and atmospheric pressure, and can be recycled and reused for 3 runs. The total turnover number of Br‐PMOF(Ir) after 3 runs was 1644 based on Ir. Mechanistic studies disclose that the high efficiency of Br‐PMOF(Ir) nanosheets was ascribed to three factors, including the superior activation capability of iridium(III) porphyrin for Si−H bonds, more active sites on the external surfaces of Br‐PMOF(Ir) nanosheets, and the defects caused by unsymmetrical porphyrin ligand that increased the framework's affinity towards CO2. [ABSTRACT FROM AUTHOR]

Oxidative stress (OS) and endoplasmic reticulum stress (ERS) are at the genesis of placental disorders observed in preeclampsia, intrauterine growth restriction, and maternal hypothyroidism. In this regard, cationic manganese porphyrins (MnPs) comprise potent redox-active therapeutics of high antioxidant and anti-inflammatory potential, which have not been evaluated in metabolic gestational diseases yet. This study evaluated the therapeutic potential of two MnPs, [MnTE-2-PyP] 5+ (MnP I) and [MnT(5-Br-3-E-Py)P]5+ (MnP II), in the fetal-placental dysfunction of hypothyroid rats. Hypothyroidism was induced by administration of 6-Propyl-2-thiouracil (PTU) and treatment with MnPs I and II 0.1 mg/kg/day started on the 8th day of gestation (DG). The fetal and placental development, and protein and/or mRNA expression of antioxidant mediators (SOD1, CAT, GPx1), hypoxia (HIF1α), oxidative damage (8-OHdG, MDA), ERS (GRP78 and CHOP), immunological (TNFα, IL-6, IL-10, IL-1β, IL-18, NLRP3, Caspase1, Gasdermin D) and angiogenic (VEGF) were evaluated in the placenta and decidua on the 18th DG using immunohistochemistry and qPCR. ROS and peroxynitrite (PRX) were quantified by fluorometric assay, while enzyme activities of SOD, GST, and catalase were evaluated by colorimetric assay. MnPs I and II increased fetal body mass in hypothyroid rats, and MnP I increased fetal organ mass. MnPs restored the junctional zone morphology in hypothyroid rats and increased placental vascularization. MnPs blocked the increase of OS and ERS mediators caused by hypothyroidism, showing similar levels of expression of HIFα, 8-OHdG, MDA, Gpx1, GRP78, and Chop to the control. Moreover, MnPs I and/or II increased the protein expression of SOD1, Cat, and GPx1 and restored the expression of IL10, Nlrp3, and Caspase1 in the decidua and/or placenta. However, MnPs did not restore the low placental enzyme activity of SOD, CAT, and GST caused by hypothyroidism, while increased the decidual and placental protein expression of TNFα. The results show that treatment with MnPs improves the fetal-placental development and the placental inflammatory state of hypothyroid rats and protects against oxidative stress and reticular stress caused by hypothyroidism at the maternal-fetal interface., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

A copper porphyrin-derived metal-organic framework electrocatalyst, FICN-8, was synthesized and its catalytic activity for CO2 reduction reaction (CO2RR) was investigated. FICN-8 selectively catalyzed electrochemical reduction of CO2 to CO in anhydrous acetonitrile electrolyte. However, formic acid became the dominant CO2RR product with the addition of a proton source to the system. Mechanistic studies revealed the change of major reduction pathway upon proton source addition, while catalyst-bound hydride (*H) species was proposed as the key intermediate for formic acid production. This work highlights the importance of electrolyte composition on CO2RR product selectivity., (© 2024 Wiley‐VCH GmbH.)

The application of half-metallic materials in single-molecule optoelectronic devices opens a promising way in advancing device performance and functionality, thus addressing a research question of significance. Here we propose a series of single-molecule devices with half-metallic FeN 4 -doped armchair graphene nanoribbon as electrodes and metalloporphyrin (MPr) molecules as photoresponsive materials for photon harvesting, which are driven by photogalvanic effects (PGEs). Through the quantum transport simulations, we systematically investigated the spin-polarized photocurrents under the linearly polarized light illumination in these devices. Since the exclusive opening only exists in the spin-up channel of the half-metallic nanoribbons, these devices can generate a large photocurrent in the spin-up direction whereas suppressing the spin-down photocurrent. Consequently, they exhibit an effective spin-filtering effect at numerous photon energies. Our study unveils the excellent spin-filtering effect achieved in single-molecule optoelectronic devices with half-metallic electrodes, showing instructive significance for the future design of new optoelectronic devices., (© 2024 IOP Publishing Ltd.)