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Porphyrins are prime candidates for a host of molecular electronics applications. Understanding the electronic structure and the role of anchoring groups on porphyrins is a prerequisite for researchers to comprehend their role in molecular devices at the molecular junction interface. Here, we use the density functional theory approach to investigate the influence of anchoring groups on Ni and Zn diphenylporphyrin molecules. The changes in geometry, electronic structure, and electronic descriptors were evaluated. There are minimal changes observed in geometry when changing the metal from Ni to Zn and the anchoring group. However, we find that the distribution of electron density changes when changing the anchoring group in the highest occupied and lowest unoccupied molecular orbitals. This has a direct effect on electronic descriptors such as global hardness, softness, and electrophilicity. Additionally, the optical spectra of both Ni and Zn diphenylporphyrin molecules exhibit either blue or red shifts when changing the anchoring group. These results indicate the importance of the anchoring group on the electronic structure and optical properties of porphyrin molecules. [ABSTRACT FROM AUTHOR]

Photomediated reversible addition fragmentation chain transfer (RAFT) step‐growth polymerization is performed using a trithiocarbonate‐based chain transfer agent (CTA) and acrylate‐based monomers both with and without a photocatalyst. The versatility of photo‐mediated RAFT step‐growth is demonstrated by one‐pot synthesis of a graft copolymer via sequential monomer addition. Furthermore, oxygen‐tolerant photo‐mediated RAFT step‐growth is demonstrated, facilitated by the appropriate selection of photocatalyst and solvent pair (zinc tetraphenyl porphyrin [ZnTPP] and dimethyl sulfoxide [DMSO]), enabling ultralow volume polymerization under open‐air conditions. [ABSTRACT FROM AUTHOR]

Due to the challenge of cleaving O−O bonds at single Co sites, mononuclear Co complexes typically show poor selectivity for the four‐electron (4e−) oxygen reduction reaction (ORR). Herein, we report on selective 4e− ORR catalyzed by a Co porphyrin with a hanged ZnII ion. Inspired by Cu/Zn‐superoxide dismutase, we designed and synthesized 1‐CoZn with a hanging ZnII at the second sphere of a Co porphyrin. Complex 1‐CoZn is much more effective than its Zn‐lacking analogues to catalyze the 4e− ORR in neutral aqueous solutions, giving an electron number of 3.91 per O2 reduction. With spectroscopic studies, the hanging ZnII was demonstrated to be able to facilitate the electron transfer from CoII to O2, through an electronic "pull effect", to give CoIII‐superoxo. Theoretical studies further suggested that this "pull effect" plays crucial roles in assisting O−O bond cleavage. This work is significant to present a new strategy of hanging a ZnII to improve O2 activation and O−O bond cleavage. [ABSTRACT FROM AUTHOR]

The question about acceptor molecules of optical radiation that determine the effects of photobiomodulation in relation to various types of cells still remains the focus of attention of researchers. This issue is most relevant for cancer cells, since, depending on the parameters of optical radiation, light can either stimulate their growth or inhibit them and lead to death. This study shows that endogenous porphyrins, which have sensitizing properties, may play an important role in the implementation of the effects of photobiomodulation, along with flavins. For the first time, using steady‐state and kinetic spectrofluorimetry, free‐base porphyrins and their zinc complexes were discovered and identified in living human cervical epithelial carcinoma (HeLa) cells, as well as in their extracts. It has been shown that reliable detection of porphyrin fluorescence in cells is hampered by the intense fluorescence of flavins due to their high concentration (micromolar range) and higher (compared to tetrapyrroles) fluorescence quantum yield. Optimization of the spectral range of excitation and the use of extractants that provide multiple quenching of the flavin component while increasing the emission efficiency of tetrapyrroles makes it possible to weaken the contribution of the flavin component to the recorded fluorescence spectra. [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]

Structurally well‐defined self‐assembled supramolecular multi‐modular donor‐acceptor conjugates play a significant role in furthering our understanding of photoinduced energy and electron transfer events occurring in nature, e. g. in the antenna‐reaction centers of photosynthesis and their applications in light energy harvesting. However, building such multi‐modular systems capable of mimicking the early events of photosynthesis has been synthetically challenging, causing a major hurdle for its growth. Often, multi‐modularity is brought in by combining both covalent and noncovalent approaches. In the present study, we have developed such an approach wherein a π‐extended conjugated molecular cleft, two zinc(II)porphyrin bearing bisstyrylBODIPY (dyad, 1), has been synthesized. The binding of 1 via a 'two‐point' metal‐ligand coordination of a bis‐pyridyl fulleropyrrolidine (2), forming a stable self‐assembled supramolecular complex (1 : 2), has been established. The self‐assembled supramolecular complex has been fully characterized by a suite of physico‐chemical methods, including TD‐DFT studies. From the established energy diagram, both energy and electron transfer events were envisioned. In dyad 1, selective excitation of zinc(II)porphyrin leads to efficient singlet‐singlet excitation transfer to (bisstyrly)BODIPY with an energy transfer rate constant, kEnT of 2.56×1012 s−1. In complex 1 : 2, photoexcitation of zinc(II)porphyrin results in ultrafast photoinduced electron transfer with a charge separation rate constant, kCS of 2.83×1011 s−1, and a charge recombination rate constant, kCR of 2.51×109 s−1. For excitation at 730 nm corresponding to bisstyrylBODIPY, similar results are obtained, where a biexponential decay yielded estimated values of kCS 3.44×1011 s−1 and 2.97×1010 s−1, and a kCR value of 2.10×1010 s−1. The newly built self‐assembled supramolecular complex has been shown to successfully mimic the early events of the photosynthetic antenna‐reaction center events. [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]

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•_$$ {\mathrm{O}}_2^{\bullet^{\_}} $$) 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•_$$ {\mathrm{O}}_2^{\bullet^{\_}} $$. 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]

The discovery of systems capable of recognizing amyloid-β protein (Aβ) oligomeric species with high sensitivity and specificity, also producing detectable signals, could represent an attractive approach for the early diagnosis of Alzheimer's disease (AD). In this regard, peptide-based inhibitors of Aβ aggregation have been extensively studied with particular attention to those derived from original amyloid sequences, such as the hydrophobic Aβ16–20 core (KLVFF). In this study we combined the antifibrillogenic action of the KLVFF peptide motif with the spectroscopic features of the porphyrin macrocycle. Specifically, we describe the synthesis of a new water-soluble zinc metallated porphyrin–peptide conjugate, in which the porphyrin macrocycle is linked via 1,2,3-triazole linkage to the hydrophobic Aβ16–20 sequence. The zinc–porphyrin–peptide conjugate was obtained by copper-catalyzed azide–alkyne cycloaddition (CuAAC) in the presence of Cu(I) as a catalyst. The "click" reaction was carried out between the azido-KLVFF peptide and the alkyne-porphyrin. The ability of the porphyrin–peptide conjugate to interact with Aβ was investigated. The zinc-metallated porphyrin–peptide conjugate was studied by biophysical techniques, including UV-vis, circular dichroism (CD), and Bis-Ans fluorescence. Finally, cell viability studies were performed on differentiated neuroblastoma cells. [ABSTRACT FROM AUTHOR]

ABSTRACT As one of the most potential platforms for heterogeneous catalysis, two‐dimensional porphyrin‐based covalent organic frameworks (COFs) have attracted great research interests. In this work, following the correlation of COF structure and their performance, a type of donor–acceptor 2D COF (Por‐COF‐Zn) based on porphyrin and thiophene units was designed and easily constructed by one‐pot method using 5,10,15,20‐tetra‐(4‐aminophenyl)porphyrin (TAPP), thieno[3,2‐b]thiophene‐2,5‐dicarbaldehyde, and zinc acetate. The as‐synthesized COF material is tested to show high crystallinity and good thermal and chemical stability. The Brunauer–Emmett–Teller (BET) measure results show that the specific surface area of Por‐COF‐Zn is 413.6 m2g−1, and the pore volume is 0.279 cm3g−1. Transient photocurrent response and EIS measurement also demonstrate that Por‐COF‐Zn exhibits an efficient separation of photogenerated electron/hole pairs. The photocatalytic performance of the resulted COF was further evaluated by using intramolecular cyclization of N‐phenyl‐o‐phenylenediamine and benzaldehyde to form benzimidazole derivative. The catalyst system exhibited good to high conversion efficiency, moderate substrate applicability, and excellent stability and recyclability for the catalytic cyclization approach of benzimidazoles. The catalytic mechanism should be contributed to the synergistic effect of organic framework and metallic zinc. Our current work also provides valuable information for understanding COF‐based photocatalytic systems and further highlight new insights to meet new challenges of heterogeneous photocatalysis. [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]

Photophysical, photovoltaic, and charge transport properties of fused core-modified expanded porphyrins containing two pyrroles, one dithienothiophene (DTT) unit, and 1–4 thiophenes (1–4) were inspected by using density functional theory (DFT) and time-dependent DFT. Compounds 1–3 have been investigated experimentally before, but 4 is a theoretical proposal whose photophysical features match those extrapolated from 1 to 3. They exhibit absorption in the range of 700–970 nm for their Q bands and 500–645 nm for their Soret bands. The rise of thiophene rings placed in front of the DTT unit in the expanded porphyrin ring causes a bathochromic shift of the longest absorption wavelength, leading to near-infrared absorptions, which represent 49% of the solar energy. All the systems show a thermodynamically favorable process for the electron injection from the dye to TiO2 and adsorption on a finite TiO2 model. The electron regeneration of the dye is only thermodynamically feasible for the smallest expanded porphyrins 1 and 2 when I−/I3− electrolyte is used. The charge transport study shows that for voltages lower than 0.4 V, junctions featuring pentaphyrin 1 and octaphyrin 4 are more conductive than those containing hexaphyrin 2 or heptaphyrin 3. The results showed that the four fused core-modified expanded porphyrins investigated are potential dyes for applications in dye-sensitized solar cells, mainly pentaphyrin 1 and hexaphyrin 2. Moreover, increasing the number of thiophene rings in the macrocycle proved fruitful in favoring absorption in the near-infrared region, which is highly desired for dye-sensitized solar cells. [ABSTRACT FROM AUTHOR]

Synthetic multimetallic porphyrinoids are potential candidates in catalysis, molecular magnetism and as modern optoelectronic materials. Introducing electronic heterogenity in these multi‐porphyrinoids shall bring in novel electronic and redox characteristics. In this direction, herein we report four discrete Corrole‐Porphyrin‐Corrole C[10] ⋅ P[5,15] ⋅ C[10] hybrids that have both corrole and porphyrin units covalently connected together. Metal ions in diverse oxidation states have been incorporated into respective cores to achieve homo and heterotrinuclear metal complexes. Selective metalation at the porphyrin and corrole cores was achieved by step‐wise insertion of Zn(II)/Cu(II), Zn(II)/Ga(III) and Cu(II)/Cu(II) ions to suit the dianionic and trianionic pockets, respectively. Single crystal X‐ray diffraction studies reveal the solid‐state structural evidence for both homo‐, and hetero‐trinuclear metal complexes. The Zn(II) and Ga(III) moieties have two distinct geometries in the molecular assembly. The geometry of Zn(II) at the porphyrin core is a perfect square planar, whereas the Ga(III) geometry at the corrole is square pyramidal with pyridine as an axial ligand. In case of homotrinuclear Cu(II) complex, the Cu(II) ions adopt square planar geometry irrespective of the core. Similar to all porphyrin trimers, C[10] ⋅ P[5,15] ⋅ C[10] trimers exhibit significant excitonic coupling between corrole and porphyrin units in the absorption spectra. The cyclic voltametric investigations also reveal electronic coupling between the individual chromophores despite the non‐coplanar arrangement amongst the individual macrocycles. [ABSTRACT FROM AUTHOR]

The photophysical properties and efficiency of photosensitized singlet oxygen formation by meso-tetrakis(4- N-methylpyridyl)porphyrin in a complex with hydroxyapatite nanoparticles were studied. At least three types of complexes characterized by different access of oxygen to porphyrin molecules were shown to form on the surface of the hydroxyapatite nanoparticles. Rotation of the pyridyl substituents of porphyrin in the complex with hydroxyapatite nanoparticles was found to be significantly hindered, while porphyrin molecules on the surface of the nanoparticles were in a less polar environment than in water. The quantum yield of photosensitized singlet oxygen formation was observed to decrease by at least nine times for porphyrin in the complex with hydroxyapatite nanoparticles. Porphyrin was released from hydroxyapatite nanoparticles and the efficiency of singlet oxygen formation increased although it did not reach the values characteristic for free porphyrin if the pH decreased to less than 5.0 (pH < 5.0). [ABSTRACT FROM AUTHOR]

Noncovalent cofacial porphyrin dimers have attracted interest due to their potential use as host materials or catalysts. In this study, we introduce a novel coordination‐directed cofacial porphyrin dimer from a meso‐tetraphenylporphyrin derivative modified with 2,2′‐bipyridine moieties at the meta positions of the phenyl groups. Spectroscopic investigation has shed light on the binding processes and the structure of the dimer in solution in detail. Initial Zn2+ ion binding to the porphyrin hinders the subsequent Zn2+ binding and the binding of the second porphyrin. However, once the dimer is formed, additional Zn2+ binding is notably enhanced, resulting in a pronounced S‐shaped binding curve. The detailed structure of the dimer in solution was established based on UV‐vis spectroscopy, various 1H NMR spectroscopy techniques and mass spectrometry. Simulations of ring‐current‐induced chemical shift changes provided evidence for the face‐to‐face porphyrin structure with tetrahedral coordination of the bipyridine ligands. The X‐ray single crystal structure provided conclusive evidence for the structure of the face‐to‐face dimer, which remarkably resembles the model structure from the 1H NMR simulation. The stability of the dimer structure makes it promising for further exploration of this motif in developing new supramolecular structures and for their potential applications as host compounds and catalysts. [ABSTRACT FROM AUTHOR]

Two structural isomeric porphyrin-based triads (Zn(II)porphyrin−Sn(IV)porphyrin−Zn(II)porphyrin) denoted as T1 and T2 were prepared from the reaction of meso-[5-(4-hydroxyphenyl)-10,15,20-tris(3,5-di-tert-butylphenyl)porphyrinato]zinc(II) (ZnL) with trans-dihydroxo-[5,10-bis(3-pyridyl)-15,20-bis(phenyl)porphyrinato]tin(IV) (SnP1) and trans-dihydroxo-[5,15-bis(3-pyridyl)-10,20-bis(phenyl)porphyrinato]tin(IV) (SnP2), respectively. All the compounds were characterized using UV–vis spectroscopy, emission spectroscopy, ESI−MS, 1H NMR spectroscopy, and FE-SEM. Most importantly, the two structurally isomeric porphyrin-based triads supramolecularly self-assembled into completely different nanostructures. T1 exhibits a nanosphere morphology, whereas T2 exhibits a nanofiber morphology. The amplified geometric feature in the structural isomeric porphyrin-based triads dictates the physical and chemical properties of the two triads. Both compounds showed the morphology-dependent visible light catalytic photodegradation of rhodamine B dye (74–97% within 90 min) and tetracycline antibiotic (44–71% within 45 min) in water. In both cases, the photodegradation efficiency of T2 was higher than that of T1. The present investigation can significantly contribute to the remediation of wastewater by tuning the conformational changes in porphyrin-based photocatalysts. [ABSTRACT FROM AUTHOR]

CdIn2S4 and zinc tetrakis(4-carboxyphenyl)porphyrin (ZnTCPP) were synthesized by hydrothermal method, and an organic dye-sensitized inorganic semiconductor ZnTCPP/CdIn2S4 type II heterojunction was constructed on a fluorine-doped tin oxide (FTO) substrate electrode. A sandwich immunostructure for signal-attenuation photoelectrochemical (PEC) detection of cardiac troponin I (cTnI) was constructed using the ZnTCPP/CdIn2S4/FTO photoanode and a horseradish peroxidase (HRP)-ZnFe2O4-Ab2-bovine serum albumin (BSA) immunolabeling complex. The bioenzyme HRP and the HRP-like nanozyme ZnFe2O4 can co-catalyze the oxidation of 4-chloro-1-naphthol (4-CN) by H2O2 to produce an insoluble precipitate on the photoanode, thus notably reducing the anodic photocurrent for quantitative determination of cTnI. Under the optimal conditions, the photocurrent at 0 V vs. SCE in 0.1 M phosphate buffer solution (pH 7.40) containing 0.1 M ascorbic acid was linear with the logarithm of cTnI concentration from 500 fg mL−1 to 50.0 ng mL−1, and the limit of detection (LOD, S/N = 3) is 0.15 pg mL−1. Spiked recoveries were 95.1% ~ 104% for assay of cTnI in human serum samples. [ABSTRACT FROM AUTHOR]

Molecular designs that achieve solubility of porphyrins in aqueous media are attractive for diverse applications. The presence of 4-sulfophenyl or 4-N-methylpyridinium groups at the four meso-positions is effective, but the use of fewer substituents is desirable for custom tailoring. Here, five target porphyrins (along with selected copper or zinc chelates) were prepared bearing PEG groups to understand how distinct designs affect aqueous solubility (where "PEG" refers to an oligoethylene glycol unit). One objective was to employ only one or two pegylated meso-aryl groups so that other meso-positions would be open for synthetic elaboration while retaining a compact structure. The key design features examined include (i) 2,6- versus 3,5-dipegylated aryl groups; (ii) one versus two 2,6-dipegylated aryl groups; (iii) a nonpolar versus ionizable terminus of the PEG moiety; and (iv) length of the PEG moiety. In each case, the PEG groups were attached on a porphyrin scaffold bearing one or two bis(2-propynyloxy)aryl groups. Assessment entailed octanol–aqueous solution partitioning (log P values) and aggregation over the concentration range of 0.2–200 μM. A trans-A2 free base porphyrin bearing two 2,6-dialkoxyphenyl groups equipped with methyl-terminated PEG6 groups gave ∼3 : 1 partitioning in water versus octanol but high overall solubility (at least 12 mM) in water alone; the analogous porphyrin with carboxylic acid-terminated PEG6 groups gave >100 : 1 partitioning in phosphate-buffered saline (PBS, pH 7.4). A trans-AB porphyrin bearing a single 2,6-dialkoxyphenyl group equipped with carboxylic acid-terminated PEG6 groups gave 43 : 1 partitioning in PBS versus octanol but was prone to self-aggregation at 20–200 μM in PBS alone. The results point to new molecular designs of potential value in the life sciences. [ABSTRACT FROM AUTHOR]

The synthesis of eight Ru(II) and Os(II) photosensitizers bearing a common 9,10-disubstituted-1,4,5,8-tetraazaphenanthrene backbone is reported. With Os(II) photosensitizers, the 9,10-diNH2-1,4,5,8-tetraazaphenanthrene could be directly chelated onto the metal center via the heteroaromatic moiety, whereas similar conditions using Ru(II) resulted in the formation of an o-quinonediimine derivative. Hence, an alternative route, proceeding via the chelation of 9-NH2-10-NO2-1,4,5,8-tetraazaphenanthrene and subsequent ligand reduction of the corresponding photosensitizers was developed. Photosensitizers chelated via the polypyridyl-type moiety exhibited classical photophysical properties whereas the o-quinonediimine chelated Ru(II) analogues exhibited red-shifted absorption (520 nm) and no photoluminescence at room temperature in acetonitrile. The most promising photosensitizers were investigated for excited-state quenching with guanosine-5′-monophosphate in aqueous buffered conditions where reductive excited-state electron transfer was observed by nanosecond transient absorption spectroscopy. [ABSTRACT FROM AUTHOR]

Apohemoprotein is focused on the field of theranostics, serving as a porphyrin carrier. Hemoglobin (Hb) consists of α2β2 tetramer with iron(II)‐protoporphyrin IX (heme) bound to each globin. However, heme‐removed Hb (apoHb) causes dissociation at αβ interfaces and aggregation under physiological conditions. We synthesized a stable apoHb derivative comprising intramolecular‐crosslinked apoHb (apoXHb) and human serum albumin (HSA), apoXHb‐HSA3. ApoXHb‐HSA3 engendered no aggregates in the physiological solutions. Moreover, apoXHb‐HSA3 was reconstituted with zinc(II)‐protoporphyrin IX (ZnP), generating ZnXHb‐HSA3, a potent photosensitizer for photodynamic therapy (PDT). The photophysical properties of ZnXHb‐HSA3 were identical to those of zinc‐substituted XHb (ZnXHb). Cellular uptake behavior was evaluated using various cancer cell lines. ZnXHb‐HSA3 released ZnP around the cells, and the free ZnP penetrated cell membranes. In contrast, protein units were not observed within the cells. ZnXHb‐HSA3 showed no cytotoxicity under dark conditions and demonstrated superior PDT activity in comparison to naked ZnXHb. ZnXHb‐HSA3 acts as an innovative porphyrin carrier for enhanced PDT. [ABSTRACT FROM AUTHOR]

For developing novel photosensitizers with therapeutic potential in non-malignant and malignant cutaneous disorders, the unsymmetrical porphyrin, 5-(2-hydroxy-3-methoxyphenyl)-10, 15, 20-tris-(4-carboxymethylphenyl) porphyrin, was evaluated in silico and in vitro. The cellular uptake of the investigated porphyrin and its ability to perform photodynamic therapy were investigated in terms of the viability, proliferation, and necrosis of human HaCaT keratinocytes and human Hs27 skin fibroblasts, in correlation with the predictions regarding diffusion through cell membranes, ADMET profile (absorption, distribution, metabolism, elimination, toxicity), and potential pharmacological mechanism. Molecular docking and 250 ns molecular dynamics simulations revealed that P5.2 has the potential to form a relatively stable complex with the carbonic anhydrase IX catalytic site, the lowest predicted free energy of binding (MM/PBSA) being −39.097 kcal/mol. The results of the in vitro study showed that P5.2 is incorporated within 24 h in the investigated cells, especially in HaCaT keratinocytes, indicating its photosensitizing ability. Nevertheless, P5.2 does not exert significant cytotoxicity in "dark" conditions. In turn, PDT induced a decrease in the number of metabolically active HaCaT keratinocytes within 24 h, accompanied by a 4-fold increase in lactate dehydrogenase release, indicating its ability to perform PDT in human skin cells. The experimental results suggest that the asymmetrical porphyrin is a promising candidate theranostics agent for skin disorders. [ABSTRACT FROM AUTHOR]

New β-amino-substituted porphyrin derivatives bearing carboxy groups were synthesized and their performance as sensitizers in dye-sensitized solar cells (DSSC) was evaluated. The new compounds were obtained in good yields (63–74%) through nucleophilic aromatic substitution reactions with 3-sulfanyl- and 4-sulfanylbenzoic acids. Although the electrochemical studies indicated suitable HOMO and LUMO energy levels for use in DSSC, the devices fabricated with these compounds revealed a low power conversion efficiency (PCE) that is primarily due to the low open-circuit voltage (Voc) and short-circuit current density (Jsc) values. [ABSTRACT FROM AUTHOR]

This study investigates the potential use of ferrocenyl‐substituted porphyrins as organic electrode materials for sodium secondary batteries. Expressly, 5,15‐di(ferrocenyl)‐10,20‐di(pentafluorophenyl)porphyrins (free base, Fc−H2Por), along with its zinc (Zn[II] complex, Fc−ZnPor) and nickel (Ni[II] complex, Fc−NiPor) derivatives were synthesized and employed as the electrode materials. The charge‐discharge processes disclosed that the ferrocenyl‐substituted porphyrin compound performs electrochemical processes poorly without chelating metals. In contrast, when the ferrocenyl‐substituted porphyrins were metalated with Ni(II) and Zn(II), they exhibited dual ionic charge‐discharge capabilities, indicating their stable electrochemical properties. In particular, long‐term cycle tests emphasized the superior stability and high Coulombic efficiency of Fc−ZnPor electrodes. Computational calculations provided conclusive evidence of variances in aromatic stabilization energy based on the metal center, significantly influencing the chemical stability and electrochemical performance. These findings can deliver valuable insight for further development and optimizations in energy storage applications. [ABSTRACT FROM AUTHOR]

Robust engineering of two-dimensional (2D) materials via covalent grafting of organic molecules has been a great strategy for permanently tuningtheir physicochemical behaviors toward electrochemical energy applications. Herein, we demonstrated that a covalent functionalization approach of graphitic surfaces including graphene by a graftable porphyrin (g-Por) derivative, abbreviated as g-Por/HOPG or g-Por/G, is realizable. The efficiency of this approach is determined at both the molecular and global scales by using a state-of-the-art toolbox including cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, atomic force microscopy (AFM), and scanning tunneling microscopy (STM). Consequently, g-Por molecules were proven to covalently graft on graphitic surfaces via C-C bonds, resulting in the formation of a robust novel hybrid 2D material visualized by AFM and STM imaging. Interestingly, the resulting robust molecular material was elucidated as a novel bifunctional catalyst for both the oxygen evolution (OER) and the hydrogen evolution reactions (HER) in acidic medium with highly catalytic stability and examined at the molecular level. These findings contribute to an in-depth understanding at the molecular level ofthe contribution of the synergetic effects of molecular structures toward the water-splitting process. [ABSTRACT FROM AUTHOR]

We report herein the electron transfer process of a novel supramolecular dyads composed of zinc tetraphenylporphyrin (ZnTPP) and zinc 5,15‐dinonyl‐10,20‐diphenylporphyrin (ZnDPP), as electron donors, and ethyl(4‐pyridyl) coumarin‐3‐carboxylate (EPCC), as an electron acceptor, through metal‐ligand coordination bond in dichloromethane. The optical absorption studies revealed the formation of the moderate stable supramolecular donor‐acceptor dyads. The fluorescence measurements showed a significant fluorescence quenching of the singlet‐excited state of the singlet‐excited states of ZnTPP and ZnDPP upon addition of different amounts of EPCC. Such quenching behavior could be attributed to the electron transfer from the singlet‐excited state of porphyrin to EPCC. The bimolecular quenching rates were determined to be 1.98×1012 and 7.59×1012 L mol−1 s−1 for ZnTPP‐EPCC and ZnDPP‐EPCC, respectively, respectively. The fluorescence lifetime measurements suggest fast and efficient intra‐supramolecular electron transfer from the singlet states of porphyrin derivatives to EPCC. Furthermore, the formation of the supramolecular dyads was confirmed by the Raman technique and computational studies. The finding that the examined zinc porphyrin ‐ coumarin supramolecular dyads absorb light in a wide range of UV‐visible spectrum, fast and efficient electron transfer render the examined supramolecular dyad as simple models for the reaction centers of the artificial photosynthetic systems. [ABSTRACT FROM AUTHOR]

Recent advances in visible light photocatalysis represent a significant stride towards sustainable catalytic chemistry. However, its successful implementation in fine chemical production remains challenging and requires careful optimization of available photocatalysts. Our work aims to structurally modify bioinspired porphyrin catalysts, addressing issues related to their laborious synthesis and low solubility, with the goal of increasing their efficiency and developing reusable catalytic systems. We have demonstrated the catalytic potential of readily available meso-tetrakis[4-(diethoxyphosphoryl)phenyl]porphyrins (M(TPPP)). Novel metal (Pd(II), Co(II) and In(III)) complexes with this ligand were prepared in good yields. These chromophores were characterized in solution using spectroscopic (NMR, UV-vis, fluorescence) and electrochemical methods. The introduction of phosphonate groups on the phenyl substituents of mesotetraphenylporphyrins (M(TPP)) improves solubility in polar organic solvents without significantly altering the photophysical properties and photostability of complexes. This structural modification also leads to easier reductions and harder oxidations of the macrocycle for all investigated complexes compared to the corresponding TPP derivatives. The free base porphyrin, zinc(II), palladium(II), and indium(III) complexes were studied as photocatalysts for oxidation of sulfides to sulfoxides using molecular oxygen as a terminal oxidant. Both dialkyl and alkyl aryl sulfides were quantitatively transformed into sulfoxides under blue LED irradiation in the acetonitrile-water mixture (10: 1 v/v) with a low loading (0.005-0.05 mol%) of porphyrin photocatalysts, where H2(TPPP) and Pd(TPPP) were found to be the most efficient. The reaction mechanism was studied using photoluminescence and EPR spectroscopies. Then, to access reusable catalysts, water-soluble derivatives bearing phosphonic acid groups, H2(TPPP-A) and Pd(TPPP-A), were prepared in high yields. These compounds were characterized using spectroscopic methods. Single-crystal X-ray diffraction analysis of Pd(TPPP-A) reveals that the complex forms a 3D hydrogen-bonded organic framework (HOF) in the solid state. Both H2(TPPP-A) and Pd(TPPP-A) were found to catalyze the photooxidation of sulfides by molecular oxygen in the acetonitrile-water mixture (1: 1 v/v), while only Pd(TPPP-A) resulted in selective production of sulfoxides. The complex Pd(TPPP-A) was easily recovered through extraction in the aqueous phase and successfully reused in five consecutive cycles of the sulfoxidation reaction. [ABSTRACT FROM AUTHOR]

In dye‐sensitized solar cells (DSSCs), flat planar dyes (e. g., highly light‐harvesting porphyrins and corroles) with multiple anchoring groups are known to adopt a horizontal orientation on TiO2 through the multiple binding to TiO2. Due to the strong electronic coupling between the dye and TiO2, fast charge recombination between the oxidized dye and an electron in TiO2 occurs, lowering the power conversion efficiency (η). To overcome this situation, an additional donor moiety can be placed on top of the planar dye on TiO2 to slow down the undesirable charge recombination. Here we report the synthesis and photovoltaic properties of a triarylamine (TAA)‐tethered gold(III) corrole (TAA‐AuCor). The DSSC with TAA‐AuCor using iodine redox shuttle exhibited the highest η‐value among corrole‐based DSSCs, which is much higher than that with the reference AuCor. The transient absorption spectroscopies clearly demonstrated that fast electron transfer from the TAA moiety to the corrole radical cation in TAA‐AuCor competes with the undesirable charge recombination to generate long‐lived charge separated state TAA⋅+‐Cor/TiO2⋅− efficiently. Consequently, the introduction of the TAA moiety enhanced the η‐value remarkably, demonstrating the usefulness of our new concept to manipulate charge‐separated states toward highly efficient DSSCs. [ABSTRACT FROM AUTHOR]

Palladium-catalyzed heterylation of monobromophenyl-substituted zinc(II) porphyrin with small heterocycles (benzothiazole, benzoxazole, and N-methylbenzimidazole) was carried out. As a result, unsymmetrical heterylphenyl-substituted zinc(II) porphyrins soluble in organic solvents were obtained. The interaction of heteryl-substituted zinc(II) porphyrins with alpha-helical proteins was studied by spectral methods using bovine serum albumin in aqueous organic solvents. It was found that the titration of the zinc(II) porphyrins with albumin in a sodium phosphate buffer involves a number of equilibria including complexation and aggregation. In the case of porphyrins containing N-methylbenzimidazole and benzoxazole residues, self-aggregation processes initiated by absorption of organic solvent molecules by the protein predominate. It was found that more hydrophobic nature of zinc(II) porphyrin with benzothiazole residue promotes the complex formation with the protein. The photochemical properties of zinc(II) porphyrin with a benzothiazole residue, capacity for the photooxidation of the alpha-helical protein, and the high affinity of protein to this porphyrin make it a promising candidate for the potential applicability for photodynamic inactivation. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) represent a promising and rapidly evolving technology in the field of photovoltaics due to their easy fabrication, low‐cost materials, and remarkable efficiency improvements over a relatively short period. However, the grain boundaries in the polycrystalline films exhibit a high density of defects, resulting in not only heightened reactivity to oxygen and water but also hampered charge transport and long‐term stability. Herein, an approach involving Zn‐porphyrin (Zn‐PP)‐upgraded antisolvent treatment to enhance the grain size and meanwhile passivate grain boundary defects in FA0.95MA0.05PbI2.85Br0.15 perovskites is presented. The Zn‐PP molecules significantly improve structural and optical properties, effectively mitigating defects and promoting carrier transport at the perovskite/hole transport layer interface. The density functional theory simulation confirms that Zn‐PP forms a strong chemical bonding with the perovskite surface. With Zn‐PP passivation, the total density of state shifts to higher‐energy regions with molecular adsorption, especially near the valence and conduction band edges, indicating that there is an increase in conducting properties of the surface with molecular adsorption. The power conversion efficiency (PCE) of PSCs increases significantly as a result of this improvement, rising from 15.38% to 19.11%. Moreover, unencapsulated PSCs treated with Zn‐PP exhibit outstanding stability, retaining over 91% of their initial PCE. [ABSTRACT FROM AUTHOR]

Chemical Communications is a journal published by The Royal Society of Chemistry, which aims to connect the world with the chemical sciences. The document provides the contents list for the current issue, including articles on topics such as the design of high-performance layered transition metal oxides for sodium-ion batteries, radical hydroboration for the synthesis of organoboron compounds, and the enantioselective synthesis of tricyclic oxoquinolines. The journal also introduces a new journal called RSC Sustainability GOLD, dedicated to sustainable chemistry and new solutions. The document includes a range of research articles covering various aspects of chemistry. [Extracted from the article]

This study effectively addresses the challenge of nitrogen adsorption and activation in photocatalytic nitrogen fixation by introducing an oxidizing co-catalyst, NiFeB hydroxides. The NiFeB hydroxides could provide reactive active sites and significantly enhance the nitrogen oxidation activity, offering a novel pathway for co-catalysts in nitrogen fixation reactions. [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]

The development of novel materials for highly efficient and selective photocatalysis is crucial for their practical applications. Herein, we employ the host‐guest chemistry of porphyrin‐based metallacages to regulate the generation of reactive oxygen species and further use them for the selective photocatalytic oxidation of benzyl alcohols. Upon irradiation, the sole metallacage (6) can generate singlet oxygen (1O2) effectively via excited energy transfer, while its complex with C70 (6⊃C70) opens a pathway for electron transfer to promote the formation of superoxide anion (O2⋅−), producing both 1O2 and O2⋅−. The addition of 4,4′‐bipyridine (BPY) to complex 6⊃C70 forms a more stable complex (6⊃BPY) via the coordination of the Zn‐porphyrin faces of 6 and BPY, which drives fullerenes out of the cavities and restores the ability of 1O2 generation. Therefore, benzyl alcohols are oxidized into benzyl aldehydes upon irradiation in the presence of 6 or 6⊃BPY, while they are oxidized into benzoic acids when 6⊃C70 is employed as the photosensitizing agent. This study demonstrates a highly efficient strategy that utilizes the host‐guest chemistry of metallacages to regulate the generation of reactive oxygen species for selective photooxidation reactions, which could promote the utilization of metallacages and their related host‐guest complexes for photocatalytic applications. [ABSTRACT FROM AUTHOR]

Psoralens are eponymous for PUVA (psoralen plus UV-A radiation) therapy, which inter alia can be used to treat various skin diseases. Based on the same underlying mechanism of action, the synthetic psoralen amotosalen (AMO) is utilized in the pathogen reduction technology of the INTERCEPT® Blood System to inactivate pathogens in plasma and platelet components. The photophysical behavior of AMO in the absence of DNA is remarkably similar to that of the recently studied psoralen 4′-aminomethyl-4,5′,8-trimethylpsoralen (AMT). By means of steady-state and time-resolved spectroscopy, intercalation and photochemistry of AMO and synthetic DNA were studied. AMO intercalates with a higher affinity into A,T-only DNA (KD = 8.9 × 10−5 M) than into G,C-only DNA (KD = 6.9 × 10−4 M). AMO covalently photobinds to A,T-only DNA with a reaction quantum yield of ΦR = 0.11. Like AMT, it does not photoreact following intercalation into G,C-only DNA. Femto- and nanosecond transient absorption spectroscopy reveals the characteristic pattern of photobinding to A,T-only DNA. For AMO and G,C-only DNA, signatures of a photoinduced electron transfer are recorded. [ABSTRACT FROM AUTHOR]

The present work deals with the preparation of porphyrin derivatives using the green synthesis method. Here the focus is on reducing the steps of the reaction scheme and using a mechanochemical C-C bonding method that minimizes the use of a solvent and makes the reaction environmentally friendly. This work is about the synthesis of meso-substituted tetraphenylporphyrin (TPP). Step I of the scheme deals with the mechanochemical synthesis of oxidizable porphyrin intermediates. In Step II, these oxidizable porphyrin intermediates are treated with effective oxidizing agents to convert them into the product. Product purity is checked primarily by UV-Visible spectrophotometry and confirmed by IR, ¹H-NMR, 13C-NMR, and MALDI-TOF instrumentation techniques. The synthesized porphyrins sensitizers are also able to generate current without any external load. Hence, they have photovoltaic importance in emerging organic photovoltaic technology-based Solar Cells. [ABSTRACT FROM AUTHOR]

Dye‐sensitized photocatalytic systems (DSPs) have been extensively investigated for solar‐driven hydrogen (H2) evolution. However, their application in carbon dioxide (CO2) reduction remains limited. Furthermore, current solar‐driven CO2‐to‐CO DSPs typically employ rhenium complexes as catalysts. In this study, we have developed DSPs that incorporate noble metal‐free components, specifically a zinc‐porphyrin as photosensitizer (PS) and a cobalt‐quaterpyridine as catalyst (CAT). Taking a significant stride forward, we have achieved an antenna effect for the first time in CO2‐to‐CO DSPs by introducing a Bodipy as an additional chromophore to enhance light harvesting efficiency. The energy transfer from Bodipy to zinc porphyrin resulted in remarkable stability (turn over number (TON)=759 vs. CAT), and high CO evolution activity (42 mmol g−1 h−1 vs. CAT). [ABSTRACT FROM AUTHOR]

Charge injection and transport interlayers based on artificial green carbon materials are imperative for a sustainable future of many classes of optoelectronic devices, including organic light-emitting diodes (OLEDs). Especially, porphyrin derivatives can act as efficient energy and charge funnels mimicking their successful photosynthetic function. Here, we report on the application of a novel green carbon material, in particular, a zinc porphyrin derivative bearing an amidine functional group (referred to as ZnP-amidine), as an electron transport material in fluorescent OLEDs based on a green-yellow co-polymer emitter. ZnP-amidine is processed from environmental friendly solvents without any annealing requirements thus being suitable for low-cost sustainable optoelectronics. It is applies as an ultra-thin interlayer between the aluminum cathode and the emissive layer to enable efficient electron transport and stable performance. This work paves the path towards low-cost green carbon materials inspired by natural processes for organic optoelectronics. [ABSTRACT FROM AUTHOR]

Zinc 3-hydroxymethyl-pyroprotopheophorbides-a esterified with a chiral secondary alcohol at the 17-propionate residue were prepared as bacteriochlorophyll-d analogs. The synthetic zinc 31-hydroxy-131-oxo-porphyrins self-aggregated in an aqueous Triton X-100 micellar solution to give red-shifted and broadened Soret and Qy absorption bands in comparison with their monomeric bands. The intense, exciton-coupled circular dichroism spectra of their self-aggregates were dependent on the chirality of the esterifying groups. The observation indicated that the self-aggregates based on the J-type stacking of the porphyrin cores were sensitive to the peripheral 17-propionate residues. The supramolecular structures of the present J-aggregates as models of bacteriochlorophyll aggregates in natural chlorosomes were remotely regulated by the esterifying groups. [ABSTRACT FROM AUTHOR]

A saddle‐shaped π‐extended zinc porphyrin containing a peripheral pyridyl ligand undergoes quantitative self‐assembly into a cyclic trimer. The trimer has a prismatic structure with negatively curved side walls, which promote the formation of supramolecular organic frameworks stabilized by dispersion interactions. The first framework type, UWr‐1, has the npo topology, with a hexagonal structure analogous to the Schwartz H triply periodic minimal surface. Co‐crystallization of the trimer with either C60 and C70 produces the isomorphous cubic UWr‐2 and UWr‐3 phases, characterized by the ctn network topology and a structural relationship to the Fischer‐Koch minimal surface S. All three phases contain complex labyrinths of solvent‐filled channels, corresponding to very large probe‐accessible volumes (68 % to 76 %). The UWr‐2 network could be partly desolvated while retaining its long range dimensional order, indicating remarkable strength of the dispersion interactions in the crystal. A theoretical analysis of noncovalent interactions shows the role of geometrical matching between the negatively curved porphyrin units and positively curved fullerenes. [ABSTRACT FROM AUTHOR]

We previously reported a cyclic Zn(II) porphyrin trimer in which three Zn porphyrins are alternately bridged by three 2,2′‐bipyridine (bpy) moieties, enabling the encapsulation of metal complexes within the nanopore formed by the Zn porphyrins. In this study, we introduced a [Re(CO)3Br] fragment into one of the bpy moieties of the cyclic trimer to form the catalytic Re(4,4'‐R2‐bpy)(CO)3Br center (R=methyl ester). The ester groups (R) play an important role in the synthesis of the cyclic structure. However, it was observed that these ester groups significantly deactivated the photocatalytic CO2 reduction reaction. Therefore, we converted the ester groups with a suitable reducing reagent into hydroxymethyl groups, followed by acetylation to form acetoxymethyl groups. This modification remarkably enhanced the photocatalytic activity of the cyclic trimer=Re complex system for CO2 reduction. Moreover, in the modified system, the presence of the Re complex induced room‐temperature phosphorescence of the Zn porphyrin. The phosphorescence was significantly quenched by 1,3‐dimethyl‐2‐phenyl‐2,3‐dihydro‐1H‐benzo[d]imidazole, indicating that efficient electron transfer mediated by the excited triplet state of the Zn porphyrin occurs during the photocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance (AMR) poses a significant global health risk as a consequence of misuse of antibiotics. Owing to the increasing antimicrobial resistance, it became imperative to develop novel molecules and materials with antimicrobial properties. Porphyrins and metalloporphyrins are compounds which present antimicrobial properties especially after irradiation. As a consequence, porphyrinoids have recently been utilized as antimicrobial agents in antimicrobial photodynamic inactivation in bacteria and other microorganisms. Herein, we report the encapsulation of porphyrins into peptide hydrogels which serve as delivery vehicles. We selected the self-assembling Fmoc-Phe-Phe dipeptide, a potent gelator, as a scaffold due to its previously reported biocompatibility and three different water-soluble porphyrins as photosensitizers. We evaluated the structural, mechanical and in vitro degradation properties of these hydrogels, their interaction with NIH3T3 mouse skin fibroblasts, and we assessed their antimicrobial efficacy against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacteria. We found out that the hydrogels are cytocompatible and display antimicrobial efficiency against both strains with the zinc porphyrins being more efficient. Therefore, these hydrogels present a promising alternative for combating bacterial infections in the face of growing AMR concerns. [ABSTRACT FROM AUTHOR]

Femtosecond lasers have been applied in the machining of zirconia ( ZrO 2 ) ceramics because of their ultrashort pulse duration and high peak power. However, the high-precision micromachining of zirconia remains challenging owing to an unclear understanding of the ultrafast laser–material interaction mechanisms. In this study, the transient processing phenomenon induced by a femtosecond laser pulse, namely electron excitation (filament), occurring on a picosecond to nanosecond timescale, was directly observed and quantitatively investigated inside ZrO 2 . A pump-probe imaging method comprising a focusing probe beam integrated with a high-speed camera was used. The evolution process, type variation, and related interaction mechanisms of the filament were revealed under different parameters, including laser pulse energy, sample position, and pulse duration. Finally, the generation mechanism of multiple filaments was clarified and successfully elucidated. This study reveals the ultrafast laser–material interaction mechanisms and the high-precision processing in the laser drilling of zirconia ceramics. [ABSTRACT FROM AUTHOR]

Photocatalytic water oxidation is a key half-reaction for various solar-to-fuel conversion systems but requires simultaneous water affinity and hole accumulation at the photocatalytic site. Here, we present the rational design and synthesis of an ionic-type covalent organic framework (COF) named tetraphenylporphyrin cobalt and cobalt bipyridine complex (CoTPP-CoBpy3) COF, combining cobalt porphyrin and cobalt bipyridine building blocks as a photocatalyst for water oxidation. The good dispersibility of porous large-size (>2 micrometers) COF nanosheets (≈1.45 nanometers) facilitates local water collection; the ultrafast triplet-state charge transfer (1.8 picoseconds) and prolonged charge separation (1.2 nanoseconds) further contribute to the efficient accumulation of holes in the CoTPP moiety, leading to a photocatalytic dioxygen production rate of 7323 micromoles per gram per hour. Moreover, we have identified an end-on superoxide radical (O2·) intermediate at the active site of the CoTPP moiety and proposed an electron-intermediate cascade mechanism that elucidates the synergistic coupling of electron relay (S1-T1-T1′) and intermediate evolution during the photocatalytic process. [ABSTRACT FROM AUTHOR]

The human eye, sensors, and photoreceptors can be damaged if they are submitted to laser beams with high intensities and low divergence. In the military field, an optical sensor can be damaged by pulsed laser radiations when exposed beyond its capacities. In order to have a protection against such threats, passive optical limiting is used. A mix between a reactive oligomer and a monomer, with methacrylate functions, is studied in the present work giving a thermoset matrix. To prevent the monomer evaporation, which results in the formation of bubbles in the final material, related to the reaction exotherm, an oligomer and a monomer with a high boiling temperature are used as precursors, giving a good alternative to a thermoplastic matrix like polymethyl methacrylate (PMMA). We report the experimental results of transient thermally induced optical nonlinearities (i.e., nonlinear refraction) in methacrylate‐based polymer filters at a nanosecond timescale, focus will be made to compare third order nonlinear refractive index from thermally induced refractive index. Optical filters are obtained by chemical bulk processes. In the present work, both thermoplastics and thermosets matrices were synthesized in order to characterize their optical limiting properties by mean of an appropriate custom‐made optical setup as well as their nonlinear refractive indices measured by the z‐scan technique. Optical measurements in the nonlinear regime are achieved at the wavelength of 1064 nm. To the best of the authors' knowledge, such a work dealing on 3D‐network methacrylate‐based host has never been published. [ABSTRACT FROM AUTHOR]

In this work, we present Zn, CoII, and MnIII metalated meso‐tetra‐[4‐(methylthio) phenyl] porphyrin ([Zn(TMtPP)], [CoII(TMtPP], and [MnIII(TMtPP)Cl]) as electrocatalysts and photoelectrocatalysts for electrochemical detection and photoelectrocatalytic degradation of pentachlorophenol (PCP). The complexes were characterized using UV‐visible spectroscopy, mass spectroscopy, and elemental analysis. Proton nuclear magnetic resonance (1H NMR) studies were only conducted for the Zn derivative. The electrochemical detection of PCP was carried out using cyclic voltammetry and chronoamperometry. [CoII(TMtPP)] showed better detection limit. For photoelectrocatalytic (PEC) degradation studies of PCP, linear sweep voltammetry and UV‐visible spectra were employed. [Zn(TMtPP)] showed better removal efficiency. The main species responsible for the PEC degradation were found to be superoxide radicals (⋅O2) and electron holes (h+). [ABSTRACT FROM AUTHOR]

NAD+ analogues, nicotinamide and nicotinamide mononucleotide (NMN+), were used to clarify the mechanism of visible-light driven selective NAD+ reduction to 1,4-NADH in a system of water soluble zinc tetraphenylporphyrin tetrasulfonate and colloidal rhodium nanoparticles dispersed with polyvinylpyrrolidone (Rh-PVP). As a result, it was found that nicotinamide was not reduced but NMN+ was reduced to the 1,4-form selectivity, the same as NAD+. In addition, the visible-light driven selective NMN+ reduction was found to be enhanced by the addition of the adenosine monophosphate part of the NAD+ structure. [ABSTRACT FROM AUTHOR]

Fumaric acid is a useful unsaturated dicarboxylic acid that serves as a precursor for the biodegradable plastics poly(butylene succinate) and poly(propylene fumarate). Currently, fumaric acid is mainly synthesised from petroleum resources such as benzene. It is therefore desirable to develop methods to produce fumaric acid from renewable resources such as those derived from biomass. In this work, an effective visible-light driven fumarate production from gaseous CO2 and pyruvate with the system consisting of triethanolamine, cationic water-soluble zinc porphyrin, zinc tetrakis(4-N,N,N-trimethylaminophenyl)porphyrin, pentamethylcyclopentadienyl coordinated rhodium(III) 2,2′-bipyridyl complex, NAD+, malate dehydrogenase (NAD+-dependent oxaloacetate-decarboxylating) and fumarase was developed. [ABSTRACT FROM AUTHOR]

In this paper, the encapsulating effect of single molecule of zinc porphyrin (Zn−P) inside semiconducting single walled carbon nanotubes (NT17) on the stability and optoelectronic properties of organic solar cells is investigated, assuming that this nano‐hybrid system will serve as the active layer in solar cell device. Making use of density functional theory (DFT), we looked at the optoelectronic characteristics of the isolated Zn−P molecules as well as two different configurations of the hybrid system that has a single Zn−P molecule inserted into NT17 (Zn−P@NT17 and Zn−P2@NT17). The addition of a zinc atom at the core of a porphyrin molecule results in the emergence of novel electronic and chemical characteristics, leading to distinct behavior compared to a free‐base porphyrin. These distinctions hold substantial implications for a range of applications, encompassing catalysis, sensing, and energy conversion processes. According to the study's outcomes, a charge transfer (CT) between the Zn−P molecules and the NT17 nanotube caused the structure to remain stable, and assuming to the electronic and optical computations the CT in Zn−P@NT17 hybrid nanosystems has been identified, along with its orientation. The results show that type II heterojunctions on filled semiconducting carbon nanotubes are likely to make them a viable choice for charge and light transport in the active layer, which can help create filled NT‐based OSCs that are extremely efficient. [ABSTRACT FROM AUTHOR]

Nanoscale optoelectrodes hold the potential to stimulate optically individual neurons and intracellular organelles, a challenge that demands both a high-density of photoelectron storage and significant charge injection. Here, we report that zinc porphyrin, commonly used in dye-sensitized solar cells, can be self-assembled into nanorods and then coated by TiO2. The J-aggregated zinc porphyrin array enables long-range exciton diffusion and allows for fast electron transfer into TiO2. The formation of TiO2(e−) attracts positive charges around the neuron membrane, contributing to the induction of action potentials. Far-field cranial irradiation of the motor cortex using a 670 nm laser or an 850 nm femtosecond laser can modulate local neuronal firing and trigger motor responses in the hind limb of mice. The pulsed photoelectrical stimulation of neurons in the subthalamic nucleus alleviates parkinsonian symptoms in mice, improving abnormal stepping and enhancing the activity of dopaminergic neurons. Our results suggest injectable nanoscopic optoelectrodes for optical neuromodulation with high efficiency and negligible side effects. Nanoscale optoelectrodes hold the potential to optically stimulate individual neuron. Here, the authors form nanoscale capacitive optoelectrodes by incorporating zinc porphyrin into nanorods, coated by TiO2, a design that allows for far-field optical modulation of neurons with efficiency and negligible side effects. [ABSTRACT FROM AUTHOR]

Introduction: Layered double hydroxides (LDHs) are widely studied anionite clays consisting of positively‐charged hydroxide nanosheets which is described by the general formula: [M(II)1−xM(III)x(OH)2][An−·mH2O], where M(II) and M(III) are the divalent (e.g., Mg2+, Zn2+, Ca2+, Co2+, Ni2+, etc.) and trivalent (e.g., Al3+, Fe3+, Cr3+, etc.) metal ions, An− and H2O is the interlamellar anion (e.g., Cl¯, Br¯, NO3¯, CO32¯, SO42¯, SeO42¯) for charge‐neutralization and hydrated state, respectively. They have been widely used in different industry sectors, in materials science and research. Polymer/LDH nanocomposites have gained significant attention in recent years. Carbon‐based nanomaterials, like fullerene, carbon nanotubes (CNT), graphene and graphene oxide have attracted significant attention. Fullerene molecules (C60, C70) are used as reinforcing material for polymers to improve their mechanical, thermal, optical, energy storage and charge transport properties. Objectives: C60‐doped ZnAl‐layered double hydroxide/polyvinyl alcohol nanocomposites were successfully synthesized and their photocatalytic activity for photodegradation of methylene blue (MB) synthetic dye was quantitatively analyzed by ultraviolet (UV) spectroscopy. The effect of C60 on the optical, structural, morphological properties, and photocatalytic activity of LDHs was investigated, and the impact of C60/LDH mass ratio and aging time on the properties was also studied. Methods: Fullerene‐doped ZnAl‐LDH/PVA nanocomposites were synthesized via urea hydrolysis and coprecipitation‐coformation method. First, 10 wt% PVA/water solution (40 mL) is added into the mixed solution containing 0.015 mol of Zn(NO3)2·6H2O and 0.005 mol of Al2(SO4)3·9H2O and titrated by 2 M of NaOH and 1 M of NaHCO3 mixed base solution to adjust pH 9. The obtained white slurry was shaken very hard and aged for 1 year. The obtained samples were marked by the mass percentage of C60 as 1% C60@LDH/PVA, 10% C60@LDH/PVA, 20% C60@LDH/PVA, and 60% C60@LDH/PVA. Results and Discussion: The basal spacing of C60‐doped ZnAl‐LDH was estimated to be 9.217 Å which is wide enough from the general LDH (~7.0 Å). The crystallite size of nanoparticles is 9.217 nm and ~6 nm by Scherrer's equation and Williamson–Hall method from the XRD data, respectively. Rice‐shaped 2D morphology was formed with 100 nm–2 μm width and 500 nm–10 μm in length by SEM. The maximal photodegradation efficiency was found with 20% of C60 doping (PD% = 96.98) after 360 min, where the sorption efficiency with this compound is very high (R% = 85.55). Conclusions: In the presented work, the effect of C60 on the optical, structural, morphological properties, and photocatalytic activity of LDHs was investigated, and the impact of C60/LDH mass ratio and aging time on the properties was also studied. For the identification of the photocatalytic activity of obtained C60/LDH nanocomposites, MB was used as a model pollutant and the efficiency of the Zn/Al LDH nanocomposite, with various quantities of fullerene, is also evaluated. [ABSTRACT FROM AUTHOR]