Magnesium Porphyrin Research Articles

Adsorption of magnesium porphyrin on Au(111)-supported graphene and hexagonal boron nitride monolayers: A first-principles study

Adsorption of magnesium porphyrin on Au(111)-supported graphene and hexagonal boron nitride monolayers: A first-principles study

Density Functional Theory Calculations of Optoelectronic Properties of Individual and Encapsulated Magnesium Porphyrin in Carbon Nanotubes for Organic Nanohybrid Solar Cells

This research discusses incorporating a single magnesium porphyrin molecule into a semiconducting single‐walled carbon nanotube (SWCNT) for solar cell applications. Using density functional theory (DFT), the study examines the optical and electronic properties of the isolated magnesium porphyrin molecule and two configurations of the hybrid system. Results show structural stability due to charge transfer between the molecule and the nanotube. Different exchange‐correlation functionals (GGA and HSE06) yield varied bandgap results, affecting light absorption. Integration of the molecule into the SWCNT reduces the bandgap. Encapsulation of the molecule influences absorption and stability under irradiation. These encapsulated systems exhibit type II heterojunction characteristics, making them promising for organic solar cells based on SWCNTs, offering potential for highly efficient solar cells.

Synthesis, crystal structure and computational studies of water and pyrazine-bound magnesium 5,10,15,20-tetrakis(3,5-dimethoxyphenyl)porphyrin

The synthesis and characterization of two magnesium porphyrins [Mg(TDMPP)(H2O)2], 1 and [Mg(TDMPP)(pyz)2], 2 where TDMPP = 5,10,15,20-tetrakis(3,5-dimethoxyphenyl)porphyrin and pyz = pyrazine have been described. The compound 1 in the presence of pyrazine forms hexa-coordinated compound [Mg(TDMPP)(pyz)2], 2. Both compounds were structurally characterized. Theoretical calculations like structure optimization, calculation of energy of molecular orbitals and simulation of electronic spectra were performed. The HOMO-LUMO energy difference in compound 2 (2.53 eV) is slightly lower than in compound 1 (2.56 eV) which supports the redshift of UV–Vis peaks on binding pyrazine to compound 1.

Bioactive porphyrin magnesium (II) complex. Synthesis, molecular structure and spectroscopic characterization. Biological activity and molecular docking studies

We have synthesized and characterized porphyrin structures by UV–visible, IR and fluorescence spectroscopy studies and single crystal XRD analysis; H2(TPP) (I) (meso-tetraphenylporphyrin), [Mg(TPP)(DMF)] (II); (DMF: dimethylformamide) and [Mg(TPP)(H2O)]0.2(4-CNpy) (III); (4-CNpy: 4-Cyanopyridine). The crystal packing of the porphyrin structures is stabilized by intermolecular hydrogen bonds and by intermolecular CH⋯Cg π interactions where Cg is the centroid of the phenyl and pyrrole rings. UV–Vis spectroscopic data confirmed the creation of Mg-meso-porphyrin complexes by the red-shifted Soret bands for our derivatives compared to the free-base porphyrin. The optical gap energy values of (I), (II) and (III) are 1.92, 2.07 and 2.00 eV. Gram-positive and Gram-negative bacteria were tested against free porphyrin (I), metallated porphyrin (II) and complex (III). The results show that the magnesium porphyrin derivative is highly effective compared to H2TPP free-base porphyrins and metallated porphyrin [Mg(TPP)] and has higher inhibition character against the tested bacteria. The molecular docking of the complex (III), in the active sites of bacterial proteins was carried out to detect the degree of antibacterial activity of recognition.

A fluorescence analysis model for assessing the water stability of porphyrinic metal−organic frameworks

Porphyrinic metal−organic frameworks (PMOFs) are a type of emerging porous material with potential applications in catalysis, biomedicine, and sensing. Despite their plentiful advantages, the applications of many PMOFs are ultimately limited by their water stability. The water stability of PMOFs is influenced by the coordination interactions between metal nodes and water molecules. In this work, based on the excellent photoluminescent properties of magnesium porphyrins, the interactions between water molecules and PMOFs with 15 metal nodes were studied and assessed by the fluorescence method. First, the ligand-to-metal charge transfer (LMCT) effect of these PMOFs was investigated. Subsequently, according to the fluorescence intensity and kinetic performance of PMOFs in ethanol with different water contents, a model for the water stability of PMOFs was established, and PMOFs were classified into three categories: water stable, relatively stable, and unstable. Finally, the water-sensitive magnesium node PMOF (MgTCPP-Mg) can serve as an excellent fluorescent probe for highly sensitive detection of trace water in organic media, particularly methanol, with detection limits as low as 0.0093 % (v/v). The establishment of this evaluation method and model helps researchers choose the appropriate PMOFs according to their needs.

Highly cross-linked bifunctional magnesium porphyrin-imidazolium bromide polymer: Unveiling the key role of co-catalysts proximity for CO2 conversion into cyclic carbonates

Highly cross-linked materials containing an imidazolium salt and magnesium porphyrin, either in the absence (TSP-Mg-imi) or in the presence (7a and 7b) of multi-walled carbon nanotubes (MWCNTs), were synthesized and used as heterogeneous bifunctional catalysts for the conversion of CO2 into cyclic carbonates. The metalloporphyrin moiety acts both as a “covalent swelling agent”, generating hybrids with high surface area, and as a Lewis acid co-catalytic species. TSP-Mg-imi produced excellent conversion and TONMg values, under solvent-free conditions, even at room temperature and with low catalytic loading (0.003 mol%). In terms of conversion and TONMg, TSP-Mg-imi exhibited better catalytic performance compared to a reference homogeneous system, demonstrating that the proximity between the metal centers and the nucleophilic site results in a synergistic effect during the catalytic cycle. The results of the computational study confirmed both the cooperative function and the significance of incorporating a co-catalytic species into the system.

Synthesis, biological evaluation and molecular docking studies of a new magnesium (II) porphyrin complex

A new bioactive material of magnesium porphyrin complex [Mg(TPP)](H2O)2].2/3(2.2.2).1/3(Bz) (I), (TPP = meso-‑tetraphenylporphyrinato and (2.2.2) = cryptand, and Bz is benzene (C6H6)) has been synthesized and characterized by Single-crystal X-ray diffraction (SCXRD). The title compound crystallizes in trigonal crystal system in space group P-3. The magnesium ion is coordinated to four nitrogen atoms of the porphyrin core and two oxygen atoms of the axial ligands. The crystal packing is stabilized by inter-and intramolecular hydrogen bonds, and by weak C–H…Cg π interactions leading to a bi-dimensional network. In order to confirm the crystal structure, the photophysical properties have been evaluated by infrared (IR), proton nuclear magnetic resonance 1H NMR and UV–Vis spectroscopy. UV–Visible absorption spectrum of complex (I) displayed a red shifted Soret (429 nm) and Q (567 and 609 nm) bands due to the extended conjugation. The IR, and 1H NMR confirm the crystal structure. Finally, bioactivity investigations revealed that free porphyrin H2TPP, [Mg(TPP)] and complex (I) could be used as potential novel significant antibacterial agents. The docking of the free base porphyrins, metallated and the complex (I), in the active sites of bacterial proteins EEscherichia coli (1ECL) and Aspergillus Niger (3K4P) was carried out to detect the degree of antibacterial activity of recognition.

Synthesis, crystal structure, computational studies, and antioxidant properties of dimethylformamide-bound magnesium tetraphenylporphyrin

The synthesis, characterization and crystal structure of a dimethylformamide (DMF) coordinated magnesium tetraphenylporphyrin, [Mg(TPP)(DMF)]·CH2Cl2 (1), is described. Theoretical studies including optimization of the geometry, simulation of the electronic spectrum and binding energy calculations were performed for the complexes using the DFT method to understand the axial coordination in magnesium porphyrins. To get insight into intermolecular interactions Hirshfeld surface analyses and plotting of the 2D fingerprint was performed. Antioxidant activity was measured for the complex which showed enhanced antioxidant activity in the presence of DMF.

Histamine-bound magnesium porphyrins: diverse coordination modes, inhibitory role in photodegradation of chlorophyll a and antioxidant activity.

The neurotransmitter histamine exists in two isomeric forms and could be an interesting ligand due to three nitrogen atoms with the possibility of binding to metals in different ways besides its crucial role in biological systems. However, no metal-histamine interaction is known in the literature. Therefore, two histamine-bound magnesium porphyrins [MgT(4-Cl)PP(hist)2] 1 and [MgT(4-Br)PP(hist)] 2 have been synthesized and structurally characterized. Interestingly, 1 is a hexa-coordinated magnesium porphyrin due to the axial coordination of two histamine molecules via the nitrogen of the aliphatic amino group with the Mg-Nhistamine distance of 2.300 Å, while 2 is penta-coordinated due to the axial coordination of one histamine molecule through the imidazole nitrogen atom with the Mg-Nhistamine distance of 2.145 Å. The diverse coordination modes of this unique ligand are explored for the first time. Theoretical studies at the level of DFT supported the binding of histamine via imidazole nitrogen atoms for complex 2. Histamine-bound magnesium porphyrins are found to be stable against the photodegradation of magnesium porphyrin in the presence of light and oxygen. Freshly isolated chlorophyll a from spinach showed similar resistivity against photodegradation. Moreover, the histamine-bound complexes showed higher antioxidant activity for 1 (92.45%) compared to the free base porphyrin (73.11%) and MgT(4-Cl)PP (75.89%).

Unique magnesium porphyrinate structure: Synthesis, characterization, and theoretical study

A new pyrazine coordinated magnesium porphyrin, [MgTClPP(pyz)2], (TClPP = meso-tetra(4-chlorophenyl)porphyrin) was synthesized and characterized using different spectroscopic techniques. A single-crystal X-ray diffraction study shows a unique magnesium porphyrinate structure with the formation of a 1D polymeric chain due to the presence of two moieties [MgTClPP(pyz)2] and [MgTClPP(H2O)2]. The plane of one porphyrin moiety is perpendicular to the plane of the other porphyrin moiety resulting in H-bonding interactions between axial ligand pyrazine of one magnesium porphyrin and water (H2O) molecule of another adjacent magnesium porphyrin. This weak intermolecular H-bonding is present between the axial ligands [-OH….N] influencing to stabilize of the polymeric chain. UV–vis spectrum of the compound shows redshift of Soret band and Q-bands on axial ligand binding. Theoretical analysis like optimization of the geometry, calculation of single-point energy, natural bond analysis, and simulation of infrared spectra was carried out using the DFT (Density Functional Theory) method. Short-range interactions such as H-bonding are quantified by the Hirshfeld surface analysis and 2D fingerprint plots. This work suggests the role of non-covalent interactions in the case of stability of coordination compounds of bridging ligands when coordinates through only one donor atom.

A combined experimental and theoretical study on the synthesis, spectroscopic characterization of Magnesium(II) porphyrin complex with DMAP axial ligand and antifungal activity

We report in the present paper the synthesis, the spectroscopic, structural, and electrochemical properties of a new magnesium(II) coordination compound namely the bis(4-dimethylaminopyridine)[meso-tetra(p-tolyl)porphyrinato)]magnesium(II) dichloromethane disolvate complex with the formula [Mg(TTP)(DMAP)2]•2CH2Cl2 (I). This species crystallizes in the triclinic crystal system with the centrosymmetric space group P-1. The crystal lattice of (I) is stabilized by C__H…Cg (Cg is the centroid of a phenyl ring) and C__H…Cl intermolecular interactions. Further insights on these weak intermolecular contacts are provided by the Hirshfeld surface analysis. This new Mg(II) porphyrin species was characterized by 1H NMR, IR, fluorescence, UV/Vis spectroscopy and ESI-HRMS mass spectrometry. A cyclic voltammetry investigation of this new metalloporphyrin was also reported. Furthermore, the bioactivity of the H2TTP free base porphyrin, the [Mg(TTP)] starting material and [Mg(TTP)(DMAP)2]•2CH2Cl2 (I) was evaluated in vitro, by examining their inhibitory effect against three strains of Candida viz. C. albicans, C. glabrata and C. tropicalis with MIC values in the range 2.5 to 10 μg.mL−1. The screening of the susceptibility of M. canis and T. rubrum clinical strains on the three porphyrinic derivatives is also reported.

Application of a new synthesized magnesium porphyrin complex in the degradation of methylene blue dye

In the present work, the synthesis, spectroscopic, physicochemical and catalytic properties of the new bis(1,3,5,7-tetraazatricyclo[3.3.1.13,7]decane)-[5,10,15,20-tetrakis(4-methylphenyl) porphyrinato]magnesium(II) hexane solvate hemihydrate complex with the formula [MgII(TTP)(HMTA)2] (I) (TTP = meso-tetratoloylphenylporphyrinato and HMTA = hexamethylenetetramin) has been reported. The compound was also characterized using IR, UV–visible, photoluminescence, H1NMR spectroscopy studies and single-crystal XRD analyses. Absorption bands, the soret band and Q bands showed a red-shift in their optical spectroscopy data, which was detected of the starting material ([MgII(TTP)] in comparison with that free base porphyrin H2TTP. The Tauc plot method was used to calculate the optical gap Eg-op value and it was 1.98 eV. As an application, a study of the degradation of methylene blue dye in aqueous solutions using complex (I) in presence and absence of H2O2 was developed. Results show that complex (I) can serve as a catalyst in the dye degradation process.

Adsorption and Catalytic Degradation of Malachite Green by a New Magnesium Porphyrin Complex

Adsorption and Catalytic Degradation of Malachite Green by a New Magnesium Porphyrin Complex

The quest for a better understanding of ethanol coordination to magnesium and zinc porphyrin: A combined experimental and theoretical study

An ethanol coordinated magnesium porphyrin [Mg(TDMPP)(C2H5OH)], (TDMPP = 5,10,15,20-tetrakis(3,5-dimethoxyphenyl)porphyrin), 1 was synthesized and characterized by single crystal X-ray diffraction method along with other standard spectroscopic techniques. This is the first known crystal structure of an alcohol bound magnesium porphyrin of tetraphenylporphyrin derivatives. Crystal structure of the compound shows a weak hydrogen bonding interaction (2.730(4) Å) between OH group of axial ethanol molecule and a peripheral methoxy group of an adjacent porphyrin molecule. This hydrogen bonding results the formation of a weak one-dimensional supramolecular structure. The fluorescence and electrochemical studies have also been performed. To explore the disadvantages of using zinc porphyrins to study chlorophyll type magnesium porphyrins, a comparison of theoretical study using DFT level was performed between compound [Mg(TDMPP)(C2H5OH)], 1 and its zinc counterpart [Zn(TDMPP)(C2H5OH)], 2. Theoretical calculations include optimization of geometry, energy of frontier molecular orbitals (FMOs), electronic transitions and global chemical indices. The global reactivity indices like η, µ and ω derived from theoretical calculations for zinc and magnesium porphyrin supports that magnesium porphyrin is more reactive than the zinc analogue. Furthermore, the Hirshfeld surface analysis was used to quantify the weak intermolecular interactions present in the crystal lattice of compound 1.

Synthesis, molecular structure, spectroscopic characterization and antibacterial activity of the pyrazine magnesium porphyrin coordination polymer

A new material of magnesium(II) polymer compound with the formula {[MgII(TPP)(pz)]• 0.5[MgII(TPP)]•CH2Cl2}n (I), (TPP) = meso‑tetraphenylporphyrinato and pz = pyrazine) was synthetized and characterized by IR, UV-visible, PL photoluminescence and 1H NMR spectroscopy studies, single-crystal XRD analyses and cyclic voltammetry. The crystal structure of (I) is made by the 1D {[Mg(TPP)(pz)]} polymeric chains (molecules I(A)) where the tetracoordinated magnesium(II) complexes [Mg(TPP)] (molecules I(B)) are located as well as the dichloromethane solvent molecules. The crystal packing of (I) is stabilized by intermolecular CH⋯Cg π interactions where Cg is the centroid of phenyl and pyrrole rings. Additionally, the photophysical properties have been evaluated by UV-visible absorption and fluorescence emission spectroscopies. The UV-visible spectrum of (I) shows a redshift Soret band value (428 nm) compared to that of the free base H2TPP porphyrin while the λmax values of the Q bands are in the range 560 – 610 nm. The optical gap of (I) was estimated at 1.99 eV. The cyclic voltammogram of the title compound presents two reversible oxidation waves and one reversible reduction wave. The HOMO and LUMO energy values were deduced from the voltammogram which are -4.96 and -2.85 eV respectively. Furthermore, bioactivity investigations revealed that the free porphyrin, the starting material [MgII(TPP)] and complex (I) could be used as potential antibacterial agents.

Building-up novel coordination polymer with magnesium porphyrin: Synthesis, molecular structure, photophysical properties and spectroscopic characterization. Potential application as antibacterial agent

The new meso-tetraphenylporphyrin magnesium(II) polymer compound with the formula {[MgII(TPP)(4,4′-bpy)]}n.n[MgII(TPP)(4,4′-bpy)2] (I), (TPP) = meso-tetraphenylporphyrinato and 4,4′-bipy = 4,4′-bipyridine) was synthetized and characterized by IR, UV–visible, photoluminescence and 1H NMR spectroscopy studies, single-crystal XRD analyses and cyclic voltammetry. From the X-ray data, it was established that the central metal Mg2+ is located on an inversion center, being octahedrally coordinated to four pyrrole nitrogen atoms of the porphyrin ring and the nitrogen atoms of the two 4,4′-bipyridine axial ligand situated in trans positions with respect to the metal center. The crystal of (I) is made by [MgII(TPP)(4,4′-bipy)2] monomer complexes and {[MgII(TPP)(4,4′-bpy)]}n polymers linked together via CH…π type intermolecular interactions leading to a three-dimensional network. The UV–visible spectrum of (I) shows that the Soret band value (432 nm) is redshifted compared to the free base H2TPP while the λmax values of the Q bands are in the range 570–610 nm. The optical gap of (I) was estimated at 2.00 eV and the cyclic voltammogram of the title compound presents two reversible oxidation waves and one reversible reduction wave. The HOMO and LUMO energy values were deduced from the voltammogram which are −4.94 and −3.06 eV respectively. The use of [MgII(TPP)(DMF)] starting material compound, {[MgII(TPP)(4,4′-bpy)]}n.n[MgII(TPP)(4,4′-bpy)2] (I) and the [MgII(TPP)(HTMA)2] (HTMA = hexamethylenetetramine) (II) as novel significant antibacterial agents was also tested.

Excitation Energy Transfer by Electron Exchange via Two-Step Electron Transfer between a Single-Walled Carbon Nanotube and Encapsulated Magnesium Porphyrin

Because of the strong photoabsorption of porphyrin and its derivatives in the visible light region, composites of porphyrin–carbon nanotubes show promise as materials for photovoltaic and photoener...

Hydration of Closely Related Manganese and Magnesium Porphyrins in Aqueous Solutions: Ab Initio Quantum Mechanical Charge Field Molecular Dynamics Simulation Study.

To the best of our knowledge, the current study based on ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) is the first to explore the difference in the hydration behavior between Mn(II)- and Mg(II)-associated porphyrins (Mn(II)-POR and Mg(II)-POR) in aqueous solution. The simulation study highlights similar and dissimilar characteristics of the structural, dynamical, and thermodynamical properties of these closely related metals bound to porphyrins in aqueous solution. The structural analysis is based on radial and angular distribution functions, coordination number distributions, and angular-radial distributions. Both hydrated systems demonstrate similar pentacoordinated structures formed via the axial coordination of one water molecule to the metal ion in addition to the four nitrogen atoms of the porphyrin ring. However, in the case of Mn(II)-POR, the formation of a distorted square pyramidal geometry was observed. It was envisaged as a weak coordination of the water molecule to the Mn(II) atom and thus higher atomic fluctuation for all atoms in contrast to that for the hydrated Mg(II)-POR. The dynamical data in terms of the mean residence times, velocity autocorrelation function, free energy, and other parameters revealed the difference in the metal binding effect because the Mn(II) atom was observed to inhibit H-bond formation more than the presence of Mg(II) atoms in the core of the porphyrin. The current study thus highlights the significant differences in the structural and dynamical properties of Mn(II)- and Mg(II)-associated porphyrin systems.

Theoretical investigation of the chlorophyll nucleus adsorption monitored with Quartz Crystal Microbalance technique: New insights on physicochemical properties

In this work, adsorption isotherms of magnesium chloride (MgCl2) and magnesium nitrate (Mg (NO3)2) onto tetraphenylporphyrin molecules (H2TPP) are achieved at three temperatures using the Quartz Crystal Microbalance (QCM) method. The equilibrium data expressing the adsorbed quantity of Magnesium per unit of adsorbent area provide interesting information to explain the adsorption mechanism. In fact, statistical physics treatment is applied to attribute new investigations to the complexation process. Some physicochemical parameters are deduced from the analytical models established by the theoretical formalism. It is found that the model describing the layer by layer (LBL) adsorption is the best to reproduce the experimental isotherms of magnesium nitrate on porphyrin. The interaction between magnesium chloride and porphyrin is explained by a mono-layer adsorption expression. The adsorption mechanisms are characterized by an energetic investigation which demonstrates that a physisorption occurs for the Mg(NO3)2-H2TPP system whereas the adsorption of MgCl2 onto H2TPP is characterized by chemical interactions.

Biomorphic CoNC/CoOx Composite Derived from Natural Chloroplasts as Efficient Electrocatalyst for Oxygen Reduction Reaction.

Natural chloroplasts containing big amounts of chlorophylls (magnesium porphyrin, Mg-Chl) are employed both as template and porphyrin source to synthesize biomorphic CoNC/CoOx composite as electrocatalyst for the oxygen reduction reaction (ORR). Cobalt-substituted chlorophyll derivative (Co-Chl) in chloroplasts is first obtained by successively rinsing in hydrochloric acid and cobalt acetate solutions. After calcining in nitrogen to 800 °C, Co-Chl is transferred to CoNC; while other parts of chloroplasts adsorbed with Co ions are transferred to CoOx retaining the microarchitecture of chloroplasts. The abundant active CoNC sites are protected by circumjacent biocarbon and CoOx to avoid leakage and agglomeration, and at the same time can overcome the poor conductivity weakness of CoOx by directly transporting electrons to the carbonaceous skeleton. This unique synergistic effect, together with efficient bioarchitecture, leads to good electrocatalytical performance for the ORR. The onset and half-wave potentials are 0.89 and 0.82 V versus reversible hydrogen electrode, respectively, with better durability and methanol tolerance than that of commercial Pt/C. Different from the traditional concept of biomorphic materials which simply utilize bioarchitectures, this work provides a new example of coupling bioderivative components with bioarchitectures into one integrated system to achieve good comprehensive performance for electrocatalysts.