Porphyrin Derivatives Research Articles

Photosensitization of asymmetric molecular, and bimolecular aliphatic-μ-bridged-meso-phenyl porphyrin

The desired asymmetric metal-free porphyrin derivatives were prepared by condensing freshly prepared the phenyl dipyrraomethane and triphenyl tetrapyrrane building blocks with the different molar ratios of acetaldehyde ([Formula: see text]CHO), and glutaraldehyde (OHC([Formula: see text]CHO, Glu). The obtained asymmetric [3+1] ([Formula: see text]Por, [Formula: see text]Por-[Formula: see text]-([Formula: see text]Por) and [2+2] ([Formula: see text]Por, [Formula: see text]-([Formula: see text] oligomer) porphyrin derivatives were characterized by UV-Vis, FT-IR, and 1H NMR. Their photoelectric properties were investigated by examining their current density-voltage (J-V) curves in dark, and under artificial sunlight, illumination using standard bulk heterojunction cell arrangements. The [Formula: see text]-V plots show that they display photosensitive semiconducting properties in the range of ([Formula: see text] = 1.7–14.5 [Formula: see text]S/cm) with negligible photovoltaic effects. All data were compared to those of symmetric metal-free [Formula: see text]Por([Formula: see text] = 33.8 [Formula: see text]S/cm). Density functional theory (DFT) is employed to validate the ground-state molecular geometry.

Cover Feature: Highly Efficient Light‐Driven CO2 to CO Reduction by an Appropriately Decorated Iron Porphyrin Molecular Catalyst (ChemCatChem 5/2023)

The Cover Feature depicts the photocatalytic CO2 reduction using for the first time the iron porphyrin derivative [FeIII(TF4TMAP)](CF3SO3)5 as molecular catalyst. In their Research Article, M. Orio, G. Charalambidis, A. G. Coutsolelos and co-workers demonstrate that after light irradiation, CO2 to CO conversion was observed, achieving excellent turnover numbers (up to 5500 TONs) and high selectivity. More information can be found in the Research Article by M. Orio, G. Charalambidis, A. G. Coutsolelos and co-workers.

Novel triphenylamine-based porphyrins: Synthesis, structural characterization, and theoretical investigation for dye-sensitized solar cell applications

In this work, we have synthesized a series of novel porphyrin derivatives, 8, 12, and 16 in high yields. The new porphyrin derivatives are equipped with different aromatic substituents at the peripheral position. The structures of the new compounds were confirmed by elemental and spectral analyses. Among these porphyrin structures, porphyrins 8, 12, and 16 were molecularly designed and synthesized based on triphenylamine (TPA), as the core donor (DTPA), linked to one, two, or three porphyrin (DPorph) moieties with different numbers of anchoring groups (AG) to generate: DTPA-π-DPorph-A(DE1), DTPA(π-DPorph-A)2(DE2) and DTPA(π-DPorph-A)3(DE3). The structural, electronic, and spectroscopic properties of the dyes have been obtained by using the density functional theory (DFT) and time-dependent-DFT calculations. Based on the DFT studies, porphyrins 8, 12, and 16 possess all thermodynamics requirements to be used for DSSCs as the HOMO values for these three porphyrins are greater than the electrolyte's redox potential (I−/I3−, -5.2 eV), while the LUMO level more negative than the conduction band of TiO2 (- 4.2 eV), which indicate that these structures are suitable as sensitizers in DSSCs. All proposed structures were estimated in the gaseous state based on their optimized ground state geometry to estimate their EHOMO, ELUMO, and HOMO-LUMO energy gaps. porphyrins 8, 12, and 16 electronic excitations were also probed using TD-DFT experiments, which were performed under the impact of time-dependent disturbances. The simulated absorption spectra of these structures revealed the porphyrins' typical Soret- and Q-bands. porphyrin 16 with tri-cyanoacrylic acid anchoring groups has a wider absorption spectrum than other porphyrins (8, 12), and their Soret- and Q-bands are red-shifted. As a final step, we analyzed and described the DSSC's performance using the concept of DFT reactivity indices. A more efficient DSSC can be built using this approach to correlate cell efficiency with molecular properties.

Synthesis and Self-Assembly of β-Octa[(4-Diethoxyphosphoryl)phenyl]porphyrins.

The β-substituted porphyrinoids commonly used to form functional assembled systems in nature yet are still scarcely used in material chemistry probably due to the laborious synthesis of these compounds. In this work, β-octa[(4-diethoxyphosphoryl)phenyl]porphyrin (2HOPPP) and its metal (Zn(II), Cd(II), Cu(II), and Ni(II)) complexes were prepared in good yields. These highly soluble chromophores were characterized in solution using spectroscopic (NMR, UV-vis, fluorescence), electrochemical, and spectroelectrochemical methods. Attachment of the electron-deficient residue (ArP(O)(OEt)2) to the porphyrin macrocycle leads to easier reductions and harder oxidations of the macrocycle for all complexes studied as compared to corresponding meso-tetra[4-(diethoxyphosphoryl)phenyl]porphyrin derivatives reported previously. We demonstrated that the strong electron-deficient character of the MOPPP porphyrins results principally from the increase in the number of electron-withdrawing groups at the periphery of the tetrapyrrolic macrocycle. Electron-deficient porphyrins are highly required in supramolecular and material chemistry in part due to their ability to form supramolecular assemblies via the coordination of axial ligands to the central metal atom. According to single-crystal X-ray data, ZnOPPP forms in the crystalline phase dimers in which each of the two tetrapyrrolic macrocycles is connected through an unusual combination of hydrogen bonding of two phosphoryl groups and the water molecules axially coordinated to the zinc atom of the partner molecule. The involvement of water molecules in porphyrin binding allows for an increase of distance between two porphyrin mean N4 planes, up to 4.478 Å. The offset of phosphoryl groups attached to the macrocycle through a 1,4-phenylene spacer withdraws the whole porphyrin macrocycle of one molecule from spatial overlap with the macrocycle of a partner molecule and increases the Zn-Zn distance up to 10.372 Å. This still unknown type of porphyrin dimers allows one to get deeper insights into the organization of naturally occurring tetrapyrrolic macrocycles. ZnOPPP also forms a labile dimeric complex in 5.3 × 10-7-5.8 × 10-5 M chloroform solutions. In contrast, other complexes prepared in this work exist as monomeric species under these experimental conditions. The self-association constant of ZnOPPP has been determined by electronic absorption spectroscopy.

Development of Wireless Power-Transmission-Based Photodynamic Therapy for the Induction of Cell Death in Cancer Cells by Cyclometalated Iridium(III) Complexes.

Photodynamic therapy (PDT), a noninvasive method for cancer therapy, involves the generation of reactive oxygen species (ROS) by the photochemical excitation of photosensitizers (PSs) to induce cell death in cancer cells. A variety of PS including porphyrin derivatives and metal complexes such as iridium (Ir) complexes have been reported. In clinical trials, red-near infrared (NIR) light (650-900 nm) is preferred for the excitation of PSs due to its deeper penetration into tissues compared with visible light (400-500 nm). To overcome this limitation, we established a PDT system that uses cyclometalated iridium(III) (Ir(III)) complexes that are excited with blue light in the wireless power transmission (WPT) system. To achieve this, we developed a light-emitting diode (LED) light device equipped with a receiver coil that receives electricity from the transmitter coil through magnetic resonance coupling. The LEDs in the receiving device use blue light (470 nm) to irradiate a given Ir(III) complex and excite triplet oxygen (3O2) to singlet oxygen (1O2) which induces cell death in HeLa S3 cells (human cervical carcinoma cells). The results obtained in this study suggest that WPT-based PDT represents a potentially new method for the treatment of tumors by a non-battery LED, which are otherwise difficult to treat by previous PDT systems.

Oxidative Probing of the G4 DNA Structure by Znp1 Porphyrin within Sequences of MYC and TERT Promotors

The formation of G4 structures in a DNA double helix competes with the complementary strand interaction. The local environment in DNA can change equilibrium of G4 structures, which are studied on single-stranded (ss) models by classical structural methods. A relevant task is to develop methods for detecting and localizing G4 structures in extended native double-stranded (ds) DNA in the promoter regions of the genome. The ZnP1 porphyrin derivative selectively binds to G4 structures and leads to photo-induced oxidation of guanine in ssDNA and dsDNA model systems. We have shown the oxidative effect of ZnP1 on native sequences of MYC and TERT oncogene promoters, which can form G4 structures. Single-strand breaks in the guanine-rich sequence because of ZnP1 oxidation and subsequent cleavage of the DNA strand with Fpg glycosylase have been identified and assigned to the nucleotide sequence. The detected break sites have been shown to correspond to sequences capable of forming G4 structures. Thus, we have demonstrated the possibility of using porphyrin ZnP1 for the identification and localization of G4 quadruplexes in extended regions of the genome. Here we have shown the novel data on a possibility of folding G4 structures in the presence of complementary strand in native DNA double helix.

Optical and Electrophysical Properties of Vinylidene Fluoride/Hexafluoropropylene Ferroelectric Copolymer Films: Effect of Doping with Porphyrin Derivatives.

Polymer films doped by different porphyrins, obtained by crystallization from the acetone solutions, differ in absorption and fluorescence spectra, which we attribute to the differences in the structuring and composition of the rotational isomers in the polymer chains. According to the infrared spectroscopy data, the crystallization of the films doped with tetraphenylporphyrin (TPP) proceeds in a mixture of α- and γ-phases with TGTG- and T3GT3G- conformations, respectively. Three bonds in the planar zigzag conformation ensures the contact of such segments with the active groups of the porphyrin macrocycle, significantly changing its electronic state. Structuring of the films in the presence of TPP leads to an increase in the low-voltage AC-conductivity and the registration of an intense Maxwell-Wagner polarization. An increased conductivity by an order of magnitude in TPP-doped films was also observed at high-voltage polarization. The introduction of TPP during the film formation promotes the displacement of the chemical attachment defects of "head-to-head" type in the monomeric units into the surface. This process is accompanied by a significant increase in the film surface roughness, which was registered by piezo-force microscopy. The latter method also revealed the appearance of hysteresis phenomena during the local piezoelectric coefficient d33 measurements.

Preparation of a copper porphyrin derivative and its surface modification for simultaneously endowing PET fibers with dyeing, flame retardant and anti-dripping performance

Polyethylene terephthalate (PET) fibers are the most numerous synthetic fibers in the world, but their flammability and high-temperature melt dripping limit their further applications. To address these issues, a copper porphyrin derivative, i.e., copper 2‑methoxy-4-(10,15,20-tris(4-((diphenylphosphoryl)oxy)-3-methoxyphenyl) porphyrin-5-yl) phenyl diphenylphosphinate (MTPD-Cu) was firstly synthesized from biomass vanillin in this paper. Then, MTPD-Cu was used for the surface modification of PET fibers via the dyeing process to prepare multifunctional PET fibers (FR-PET) with dyeing, flame retardant and anti-dripping properties. The flame retardancy, thermal stability, anti-dripping and color fastness of FR-PET were evaluated by limiting oxygen index (LOI), burning test, micro combustion calorimetry (MCC), thermogravimetric analyzer (TGA), and water washing color fastness test. The results revealed that the LOI value increased from 21% for pure PET fibers to 29.8% for FR-PET fibers. Meanwhile, compared to pure PET fibers, the total heat release (THR) and peak heat release rate (PHRR) of FR-PET decreased by 79.8% and 57.8%, respectively. The residual char of FR-PET was significantly improved whether in nitrogen or in air atmosphere at 800 °C, showing good char forming ability. In addition, FR-PET exhibited no melt dripping phenomenon and was pink with excellent color fastness to washing. Furthermore, the possible flame retardant and anti-dripping mechanisms were also proposed. This work provides a simple and easy modification method to simultaneously endow PET fibers with dyeing, flame retardancy and antibacterial properties, which is easy to be prepared on a large scale.

Organization of the Interfacial Film of Nanoemulsions Stabilized by Porphyrin Derivatives.

Photodynamic therapies combining the action of a photosensitizer (PS), molecular oxygen, and light make it possible to destroy certain infectious sites and tumors. The incorporation of photosensitizers in nanocarriers allows for better control of their distribution in tissues and increases their concentration in the area that will be then illuminated. Nanoemulsions of glyceryl trioctanoate (GTO) have been designed in which pyropheophobide a (Pyro-A) or its lipid conjugate (Pyro-Lipid) are both stabilizing and photostimulable agents. In this work, we studied by surface pressure measurements and Brewster angle microscopy (BAM) analysis the organization of the interfacial films of nanodroplets. Comparison of preformed porphyrin nanoemulsions and two porphyrin-GTO mixtures, one mimicking the composition of the nanoemulsions and the other that of a porphyrin-rich interfacial film, highlighted the role of GTO and porphyrin derivatives in the formation, organization, and elasticity of the interfacial films in nanoemulsions. Pyro-Lipid and GTO can mix, and some of the GTO molecules remain inserted in the interfacial film at high surface pressures. In contrast, Pyro-A and GTO do not mix well and tend to segregate, leaving Pyro-A alone in the condensed interfacial film. The results of this study demonstrate the importance of characterizing the interfacial properties of porphyrin derivatives and their interaction with the oil to design stable nanoemulsions with well-controlled optical properties.

Algal-derived macromolecules and their composites: From synthetic biology to biomedical applications in bone and cardiovascular tissue engineering

Algae have shown numerous advantages as biofunctional and bioactive material sources. The development of biosynthetic or synthetic materials has enabled algal-derived macromolecules and their derivatives to be used in biomedical applications. This review examines and analyzes the most recent developments in the production of biomaterials from algal-derived macromolecules and their composites and their potential applications in bone and cardiovascular tissue engineering. Several macromolecules derived from algal polysaccharides, including sulfated polysaccharides, fucoidans, and fucans, have been developed for cartilage, intervertebral disc, bone, and skeletal muscle transplants because of their stable structures. Alginates, fucoidans, chitin, porphyrin, and other algal polysaccharide derivatives have been investigated for engineering blood vessels, heart valves, and even the liver. One advantage of algal-derived macromolecules and composites is their safe immunity properties. This review also highlights cutting-edge developments in applying algal-derived macromolecules with a broader biomedical scope to encourage in-depth research into their potential as biomaterial scaffolds in medical applications.

Ambipolar Behavior of a Cu(II)–Porphyrin Derivative in Ternary Organic Solar Cells

Ternary architecture is a promising strategy to achieve high efficiency in organic solar cells. The alignment of third‐component frontier orbitals with those of donor and acceptor (D and A) is of essential importance. Herein, a new molecule VC11, consisting of a Cu(II)–porphyrin core linked to dicyanovinylene terminal acceptor units through (E)‐1,2‐di(thiophen‐2‐yl) ethene bridges, is described. The highest occupied molecular orbital and lowest unoccupied molecular orbital values of VC11 are −5.52 and −3.74 eV, respectively, lying between the corresponding values of PBDB‐T donor and Y6 acceptor, compounds used in the construction of the studied devices. The measured electron and hole mobilities reveal similar values, in the order of 10−4 cm2 Vs−1, indicating the ambipolarity of VC11, that can be used as donor or acceptor. The organic solar cells (OSCs) based on PBDB‐T:VC11, VC11:Y6, and PBDB‐T:Y6 show power conversion efficiencies (PCEs) of 10.84%, 7.89%, and 11.98%, respectively. VC11 is utilized along with PBDB‐T and Y6 to form a ternary active layer for assembling bulk heterojunction OSCs affording a remarkable PCE of 15.25%, significantly higher than those obtained for the corresponding binary devices. This enhancement of PCE originates from the additional charge separation offered by a cascaded energy‐level alignment and a fast charge transfer, due the ambipolarity of VC11.

Weak Affinity Chromatography Using Organic Solvents on Cyanopropyl- and Arene-Modified Silica-Gel Columns—Structural Demands for Host and Guest Moieties and Effect of Solvents

Abstract Weak affinity chromatography (WAC) is effective for isolating target compounds from analogous compounds with similar functional groups. Previously, a few chromatographic behaviors based on WAC using organic solvents were observed in a series of cyclic multiporphyrin systems on cyanopropyl-modified silica gel (CN-MS). Here, three cyclic porphyrin trimers with various rigidity were examined on CN-MS to understand the mechanism of the specific interactions between porphyrin derivatives and functional groups on modified silica gel. In addition to CN-MS, six modified silica-gel columns were tested to compare their retention abilities for a cyclic nickel porphyrin dimer (C4Ni2MsCP2). We examined the cosolvent effects of the pyridine eluents for C4Ni2MsCP2. Apparent dissociation constants of C4Ni2MsCP2 with functional groups on the MS columns and effective amounts of the functional groups were estimated by frontal affinity chromatography (FAC). 1H NMR titrations of acetonitrile and nitrobenzene to C4Ni2MsCP2 were conducted to compare their association constants with movable guest molecules to the dissociation constants with immobilized functional groups obtained in FAC. We found rigidity of cyclic porphyrin derivatives and immobilization of functional groups on silica gel is necessary for significant retentions using WAC. The affinity interaction does not occur at the center of C4Ni2MsCP2, but probably occurs on the surface composed of a bipyridyl moiety and the adjacent edges of the two porphyrins. Polar solvents, such as nitrobenzene, acetonitrile, and methanol, weakened the interaction. Although C4Ni2MsCP2 dissolves well in chloroform, the interactions between C4Ni2MsCP2 and the MS columns are considerably strengthened in the presence of chloroform. The competitiveness of solvents and cosolvents with the interaction of the porphyrin on WAC is independent of the solubility of the analyte.

Molecular Engineering of Metalloporphyrins for High-Performance Energy Storage: Central Metal Matters.

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 A2 B2 -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.

Enhanced nonlinear optical performance of perovskite films passivated by porphyrin derivatives

A novel passivation strategy via the coordination between porphyrin derivatives and perovskite ionic defects is reported and demonstrated to enhance the nonlinear optical performance of perovskite materials.

Artificial tongue based on carbon dots and a porphyrin derivative for pattern recognition of metal ions

An array-based artificial tongue consisting of C-dots, TMPyP (porphyrin derivative) and a C-dot–TMPyP complex for the discrimination of different metal ions.

Chemical Profile of Essential Oil, Extracts and Fractions of Eugenia pyriformis Cambess. and its Antioxidant, Cytotoxic and Allelopathic Activities

HIGHLIGHTS Eugenia pyriformis essential oil (EO) of the leaf contains linalol, terpinen-4-ol; 2-carene; The extract showed β-amiryn (1) and the porphyrin derivatives; The extracts of the leaf and stem showed antioxidant activity; The hexane extract of the stem showed allelopathic activity.

Microwave absorbing characteristics of porphyrin derivates: a loop of conjugated structure.

Microwave absorbing architectures have gained a great deal of attention due to their widespread application in diverse fields, especially in refining electromagnetic pollution. The aim of this study is to investigate the metamaterial characteristics of porphyrin derivatives as conjugated rings in the microwave region and evaluate the influence of electron-withdrawing and donating groups on microwave attenuating performance. Initially, an innovative microwave curing procedure was applied to synthesize the derivates; following that, the phenyl, aniline, and nitrophenyl-coupled structures were identified by XRD, FTIR, FESEM, and DRS analyses. The optical features illustrated that the characteristic band gap of the conjugated loops is obtained and that the optical performance can be manipulated by coupling the functional groups. Eventually, the achieved results demonstrated that the best microwave absorbing performance is related to aniline-coupled porphyrin with a maximum reflection loss (RL) value of -104.93 dB at 10.09 GHz with 2.80 mm in thickness attaining an efficient bandwidth (EB) (RL ≤ 10 dB) higher than the X-band. Noticeably, polyethylene (PE) was applied as an absorbing matrix presenting a meaningful idea for the development of practical microwave absorbers as a new generation of electromagnetic refining and stealth materials. The presented research provides precious inspiration to tailor novel microwave absorbing materials with metamaterial capability to promote their microwave absorbing performance.

A biocompatible pure organic porous nanocage for enhanced photodynamic therapy.

Porphyrin-based photosensitizers have been widely utilized in photodynamic therapy (PDT), but they suffer from deteriorating fluorescence and reactive oxygen species (ROS) due to their close π-π stacking. Herein, a biocompatible pure organic porphyrin nanocage (Py-Cage) with enhanced both type I and type II ROS generation is reported for PDT. The porphyrin skeleton within the Py-Cage is spatially separated by four biphenyls to avoid the close π-π stacking within the nanocage. The Py-Cage showed a large cavity and high porosity with a Brunauer-Emmett-Teller surface area of over 300 m2 g-1, facilitating a close contact between the Py-Cage and oxygen, as well as the fast release of ROS to the surrounding microenvironment. The Py-Cage shows superb ROS generation performance over its precursors and commercial ones such as Chlorin E6 and Rose Bengal. Intriguingly, the cationic π-conjugated Py-Cage also shows promising type I ROS (superoxide and hydroxyl radicals) generation that is more promising for hypoxic tumor treatment. Both in vitro cell and in vivo animal experiments further confirm the excellent antitumor activity of the Py-Cage. As compared to conventional metal coordination approaches to improve PDT efficacy of porphyrin derivatives, the pure organic porous Py-Cage demonstrates excellent biocompatibility, which is further verified in both mice and rats. This work of an organic porous nanocage shall provide a new paradigm for the design of novel, biocompatible and effective photosensitizers for PDT.

Conducting 1D nanostructures from light-stimulated copper-metalated porphyrin-dibenzothiophene.

Control over the dimensionality of stimulated organic semiconductors has aroused significant interest in organic electronics; however, the design of such materials still remains to be decided. Herein, we have developed three dibenzothiophene-appended freebase, zinc-metalated and copper-metalated porphyrin derivatives (PFb-DBT, PZn-DBT and PCu-DBT) in which PCu-DBT leads to an anion-binding complex in chloroform upon the application of light, resulting in self-assembled 1D nanostructures with high electrical conductivity. Nevertheless, light-stimulated freebase and zinc-metalated P-DBT undergo protonation and demetalation. Electron microscopic images displayed the anion-binding-assisted 1D nanostructure using weak non-covalent interactions, which promotes enhancement in electrical conductivity among other things, as confirmed by electrochemical impedance spectra. Thus, the generation of well-defined nanostructures with improved electronic characteristics from stimuli-responsive organic dyes suggests the importance of developing various smart materials for efficient field effect transistors and sensors.

Efficient solar hydrogen production of zinc trimesityl porphyrin-based photocatalysts

Dye-sensitized photocatalytic systems (DSPs) have emerged as a promising strategy to achieve efficient and stable solar-driven H2 evolution systems. In this work, we prepared and tested a series of zinc-trimesityl porphyrin carboxylic acid derivatives as photosensitizes in DSPs for H2 evolution. In order to unveil the influence of the anchoring group, different positions of the carboxylic acid were studied. All porphyrins were adsorbed onto platinum-doped titanium dioxide nanoparticles (Pt-TiO2 NPs) and were irradiated by a white LED source. The DSPs coated with Zn-TM(pCOOH)P(i.e. the carboxylic acid at the para-phenyl position) illustrated increased stability (2514 TONs for 1.0 × 10[Formula: see text] M) and the highest H2 evolution activity (1959 mmol g[Formula: see text] h[Formula: see text] for 1.5 × 10[Formula: see text] M). These results reveal that efficient and stable DSPs for H2 evolution can be developed by utilizing porphyrin derivatives as photosensitizers.