Phenyl Porphyrin Research Articles

Crystal structure and self-assembly property of sandwich-type mixed (phthalocyaninato)(porphyrinato) rare earth double-decker complexes

Two sandwich-type mixed (phthalocyaninato)(porphyrinato) rare earth double-decker complexes, M(Pc)(TPP) [H2Pc=phthalocyanine; H2TPP=meso-tetra(phenyl)porphyrin] (M=Eu, Lu) (1, 2) were synthesized and the structure of Lu(Pc)(TPP) was characterized by X-ray single-crystal diffraction method. Crystal data: triclinic, space group P1¯, Z=2, C77H45Cl3LuN12, Mr=1419.57, a=12.573(5), b=12.911(5), c=22.935(5)Å, α=103.793(5)°, β=101.363(5)°, γ=93.682(5)°, V=3521(2)Å3, μ(Mo Kα)=1.196mm−1, F(000)=1426, R=0.0590, and wR=0.1639 for 9745 observed reflections with I>2σ(I). X-ray analysis reveals that the coordination polyhedron adopts a slightly distorted square-antiprismatic structure around the metal center. Both phthalocyanine and porphyrin ligands are saucer-shaped, with the skew angle of the two ligand planes approximately 45°. The self-assembled nano-structures of both complexes 1 and 2 were systematically investigated by electronic absorption and Fourier transform infrared (FT-IR) spectroscopy, transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), and X-ray diffraction (XRD) techniques, revealing the effect of molecular structure on the dimension of self-assembled nano-structures.

High-efficiency switching effect in porphyrin-ethyne-benzene conjugates

We have explored the electronic transport properties of porphyrin-ethyne-benzene conjugates using an ab initio method. The results indicate that these ethyne-bridged phenyl porphyrin molecules can be used as candidates for molecular switching devices. The coplanar conformation of phenyl and porphyrin moieties allows a far larger current than the perpendicular conformation due to the near vanishing overlap of the frontier molecular orbitals (π channels) in the porphyrin and phenyl parts in the latter. Higher current ratios of ON/OFF states can be obtained if amino or nitro substituent is placed at the position meta to the bridge connecting the π systems of the molecule. The substituent group affects the electronic state energy of the entire molecule in coplanar conformation, while only affecting the local part in perpendicular conformation. More complex ethyne-bridged diphenyl porphyrin molecules are found to yield more complex and interesting switching effects. Our results suggest that such molecular wires composed of appropriate π-conjugated molecules, can generally display perfect switching function and the efficiency can be tuned flexibly by adding certain substituent groups to the conjugates.

Oxidation of benzyl alcohols to the corresponding carbonyl compounds catalyzed by copper (II) meso-tetra phenyl porphyrin as cytochrome P-450 model reaction

Abstract The oxidation of benzyl alcohols has been studied in the presence of isobutyraldehyde as co-catalyst, molecular oxygen as oxidant and copper (II) meso-tetra phenyl porphyrin (CuTPP) as catalyst. The CuTPP catalyst exhibits good activity and high selectivity under mild conditions. The effects of temperature and solvents have also been investigated in this catalyst system.

Catalytic activity of immobilized metalloporphyrins prepared by synchronously synthesizing and immobilizing porphyrins on polymeric microspheres

AbstractA novel route to immobilize metalloporphyrins on polymeric supports was put forward, and it is the way to synchronously synthesize and immobilize porphyrins on polymeric microspheres, followed by metal salt coordination reaction. Copolymeric microspheres (GMA/MMA) of glycidyl methacrylate (GMA) and methyl methacrylate (MMA) were prepared, and then via the ring‐opening reaction of the epoxy groups on GMA/MMA microspheres, parahydroxybenzaldehyde (HBA) was bond onto the microspheres, obtaining the modified microspheres HBA‐GMA/MMA. Subsequently, the Adler reaction between solid‐liquid phases was carried out with HBA‐GMA/MMA microspheres and pyrrole as well as benzaldehyde derivate in a solution as coreactants. As a result, it was successfully realized to synchronously synthesize and immobilize porphyrin on the surfaces of GMA/MMA microspheres, resulting in three porphyrin‐immobilized microspheres, PP‐GMA/MMA (PP: phenyl porphyrin), CPP‐GMA/MMA (CPP: 4‐chlorophenyl porphyrin) and NPP‐GMA/MMA (NPP: 4‐nitrophenyl porphyrin). Further, the coordination reaction of these immobilized porphyrins with cobalt salt was conducted, obtaining three supported cobalt porphyrin catalysts, CoPP‐GMA/MMA, CoCPP‐GMA/MMA and CoNPP‐GMA/MMA. The catalytic properties of these supported mettaloporphyrin catalysts were examined in the catalytic oxidation of ethylbenzene to acetophenone by dioxygen. The experimental results indicate: (1) the prepared three solid catalysts are effective in the catalytic oxidation of ethylbenzene to acetophenone by dioxygen; (2) for these polymer‐supported metalloporphyrin catalysts, some factors, such as the substitute species on phenyl ring in the macrocycle, the immobilization density of metalloporphyrin and the added amount of the catalyst in the reaction system, affect the catalytic activity greatly; (3) the prepared supported metalloporphyrin catalysts have fine recycle and reuse property. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Preparation and preliminary evaluation of [67Ga]-tetra phenyl porphyrin complexes as possible imaging agents

[67Ga]labeled tetraphenyl porphyrin ([67Ga]-TPP) was prepared using freshly prepared [67Ga]GaCl3 and tetraphenyl porphyrin (TPPH2) for 30–60 min at 25 °C (radiochemical purity: >97 ± 1% ITLC, >98 ± 0.5% HPLC, specific activity: 13–14 GBq/mmol). Stability of the complex was checked in final formulation and human serum for 24 h. The partition coefficient was calculated for the compound (log P 1.89). The biodistribution of the labeled compound in vital organs of wild-type rats was studied using scarification studies and SPECT imaging up to 24 h. A detailed comparative pharmacokinetic study performed for 67Ga cation and [67Ga]-TPP. The complex is mostly washed out from the circulation through kidneys and can be an interesting tumor imaging/targeting agent due to low liver uptake and rapid excretion through the urinary tract.

In-Gel Staining of Proteins in Native Poly Acryl Amide Gel Electrophoresis Using Tetrakis(4-sulfonato phenyl)porphyrin

Protein identification in polyacrylamide gel electrophoresis (PAGE) requires post-electrophoretic steps like fixing, staining and destaining of the gel, which are time-consuming and cumbersome. We have developed a method for direct visualization of protein bands in PAGE using tetrakis(4-sulfonato phenyl)porphyrin (TPPS) as a dye without the need for any post electrophoretic steps, where separation and recovery of enzymes become much easier for further analysis. Activity staining was done to prove that the biochemical activity of the enzymes was preserved after electrophoresis.

Porphyrin based hybrid borate glasses: Structure and photophysical investigation

Freebase tetra phenyl porphyrin (H 2TPP) and its derivatives in different concentration ranges (0.5–2.0 mg per 12 g of boric acid) were incorporated into borate glass matrix by melt quenching technique at 230 °C. The formed glasses were stable and in green colour. The optical absorption and emission properties are different from that observed in solutions. The absorption spectrum shows a two line pattern Soret band at 435–454 nm and Q-band at 665–701 nm. The emission spectrum shows strong S 2 → S 0 emission at 490–520 nm region and S 1 → S 0 emission at 725–810 nm. The time resolved fluorescence decay of S 1 → S 0 emission shows three exponential decay. For example, in the case of 2 mg of H 2THP doped glass the lifetimes were found to be τ 1 = 0.511 ns (26.7%), τ 2 = 10 ps (64.68%) and τ 3 = 3.965 ns (8.62%). These unusual photophysical properties were found to arise from different structural motifs of porphyrin in the glass. These structures were further modeled through reactions of porphyrin with BF 3O(C 2H 5) in solution and DFT calculations.

Resonance Raman Spectroscopy of Helical Porphyrin Nanotubes

We report polarized resonance Raman data of tetrakis(4-sulfonato)phenyl porphyrin (TSPP) aggregates in solution and deposited on Au(111) at wavelengths resonant with the red-shifted (J-band) and blue-shifted (H-band) components of the split Soret (B) band. We also report scanning tunneling microscopy (STM) images which reveal that the aggregate on Au(111) is a nanotube with a 2 nm wall thickness which tends to flatten on the substrate. Relative Raman intensities and their dependence on polarization of the incident and scattered light are found to vary greatly for H- and J-band excitation, revealing a much greater degree of coherence for the J-band, in agreement with the resonance light scattering spectrum. The J-band transition is found to have transition moment components both parallel and perpendicular to the long axis of the nanotube, consistent with a helical nanotube structure. The intensity increase of the Q-band on aggregation and the weak intensity of the H-band in both the absorption and the resonance light scattering spectra are explained by vibronic B-Q coupling, which is permitted in the lowered site symmetry of the aggregate. The resonance Raman data presented here provide insight into the molecular basis for the hierarchal structure of the aggregate.

Enhanced photoactivity of CuPp-TiO 2 photocatalysts under visible light irradiation

Three novel porphyrins, 5,10,15-tri-phenyl-20-[4-(3-phenoxy)-propoxy]phenyl porphyrin, 5,15-di-phenyl-10,20-di-[4-(3-phenoxy)-propoxy]phenyl porphyrin and 5-phenyl-10,15,20-tri- [4-(3-phenoxy)-propoxy]phenyl porphyrin, and their corresponding copper(II) complexes were synthesized and characterized spectroscopically. The photocatalytic effects of TiO 2 samples impregnated with copper(II) porphyrins was investigated by photodegradation of 4-nitrophenol (4-NP) in aqueous solution under visible light. The photocatalysts were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–vis spectra and FT-IR spectra. The results indicated that CuPps were successfully loaded and interacted with the surface of TiO 2 microsphere, which is crucial to enhance the activity of the catalytic composite under visible light.

Ultrafast Exciton Dynamics of J- and H-Aggregates of the Porphyrin-Catechol in Aqueous Solution

The aggregation behavior of 5,10,15-trisphenyl-20-(3,4-dihydroxy phenyl) porphyrin (L) in aqueous solution has been studied as a function of pH and concentration with the help of steady state absorption and emission spectroscopy. Our studies revealed that, for a particular concentration range, molecules of L undergo a reversible aggregation process and form two different aggregates at two different pH ranges, namely, J- and H-aggregates. We have monitored the excited state lifetimes of different aggregates by picosecond time-resolved emission spectroscopy and found that the emission lifetime of L reduces drastically with the formation of these aggregates. To study the dynamics associated with the excited state of both non-aggregated and aggregated (both J and H) porphyrins in an ultrafast time domain, we have carried out femtosecond transient absorption spectroscopy in the visible region following excitation of the respective samples at 400 nm. In addition to other de-excitation channels, another extra 100 fs (major) component for H-aggregates and 200 fs (major) component for J-aggregates has been observed and attributed to the exciton decay components of the respective aggregates.

Differential pulse voltammetric determination and catalytic oxidation of sulfamethoxazole using [5,10,15,20‐ tetrakis (3‐methoxy‐4‐hydroxy phenyl) porphyrinato] Cu (II) modified carbon paste sensor

Sulfamethoxazole (SM) is a sulfonamide bacteriostatic antibiotic. Its primary activity is against susceptible forms of streptococcus, staphylococcus aureus, escherichia coli, haemophilus influenzae, and oral anaerobes. It is commonly used to treat urinary tract infections. In addition it can be used as an alternative to amoxicillin-based antibiotics to treat sinusitis. It can also be used to treat toxoplasmosis. In the present work, a metalloporphyrin modified carbon paste sensor was fabricated and the electrochemical behaviour of SM was studied using differential pulse voltammetry (DPV). Cu (II) complex of 5,10,15,20- tetrakis (3-methoxy-4-hydroxy phenyl) porphyrin (TMHPP Cu (II)) was used as the active material. Compared with bare carbon paste electrode (CPE), the TMHPP Cu (II) modified CPE exhibits excellent enhancement effect on the electrochemical oxidation of SM. A well-defined oxidation peak of SM occurs at -140 mV in 0.1 M phosphate buffer solution (PBS) of pH 6. All the experimental parameters were optimized and it was found that under optimum conditions the oxidation peak current was linear to the concentration of SM in the range of 1.0 x 10(-2)-1.0 x 10(-8) M with a detection limit of 1.5 x 10(-9) M. The developed sensor has been successfully applied for the determination of SM in pharmaceutical formulations and urine sample.

Photocatalytic Activity of Novel Tin Porphyrin/TiO2 Based Composites

Three dichloro Sn(IV) porphyrins, trans-dichloro[5,10,15,20-tetra-[2 or 3 or 4-(3-phenoxy)-propoxy]phenyl porphyrin]tin(IV) and the corresponding dihydroxo Sn(IV) porphyrins trans-dihydroxo[5,10,15,20-tetra-[2 or 3 or 4-(3-phenoxy)-propoxy]phenyl porphyrin]tin(IV) were synthesized and characterized spectroscopically. The dihydroxo Sn(IV) porphyrin−TiO2 composites were also prepared and characterized, and an interaction between TiO2 and tin porphyrin molecules involving the axial −OH ligand with the TiO2 surface was proposed. The photocatalytic activity was investigated by testing the photodegradation of 4-nitrophenol (4-NP) in aqueous solution under both visible and UV−vis light irradiation. It was found that the distinct space tropisms of peripheral substituents in meso sites of the porphyrin ring lead to different efficiencies in photodegrading the 4-NP.

Metalloporphyrin covalently bound to silica. Preparation, characterization and catalytic activity in oxidation of ethyl benzene

Abstract Manganese(III) porphyrin complexes [Mn(TMCPP)] [TMCPP: 5, 10, 15, 20-tetrakis (4-methoxy carbonyl phenyl) porphyrin] were grafted on the organo-functionalized silica gel. This new catalyst was characterized by UV–Vis, FTIR, surface area measurements and elemental analysis, and it was used as catalyst in the oxidation of ethyl benzene by different oxidants such as hydrogen peroxide. The manganese porphyrin catalyst proved to be efficient and selective for synthesis of acetophenone. This catalyst showed a reasonable conversion (48%), and excellent selectivity (96.6%), when tert -butyl hydroperoxide in organic solvent was used as oxidant.

Use of Tetra-ammonium Tetrakis(4-Sulphonato)Phenyl Porphyrin forPseudomonasandBacillusCell Imaging

The use of tetraammonium tetrakis(4-sulphonato)phenyl porphyrin (TPPS), a water-soluble anionic compound, as a stain to analyse bacterial cells using fluorescent microscopy was investigated. TPPS was effectively used to analyse two different bacteria: Pseudomonas aeruginosa and Bacillus cereus. The variation in brightness with varying concentrations of TPPS was studied. The patterns of variations for these bacteria were found to be the same, but with consistently higher brightness for Bacillus cereus.

Selective photocatalytic epoxidation of cyclooctene by molecular oxygen in the presence of porphyrin sensitizers

Photooxidation of cyclooctene by molecular oxygen in the presence of tetraphenyl porphyrin (H2TPP), tetramesityle porphyrin (H2TMP), tetrakis dichlorophenyl porphyrin (H2TDCPP) and ClFeTMP, ClFeTPP, tetrakis pentaflouro phenyl porphyrin iron chloride (ClFeTPFPP), ClFeTDCPP, ClMnTPP, ClMnTPFPP, ZnTDCPP, ClMnTDCPP, ClCoTDCPP, ClCoTPP and ZnTPP as sensitizers has been studied. 98% cyclooctene conversion with 97% selectivity toward cyclooctene oxide was obtained by H2TDCPP and ZnTDCPP sensitizers. The effect of electron-donating and withdrawing groups on the porphyrin macrocycle ring showed that non-metalled porphyrins with electron-withdrawing groups have higher reactivity (H2TDCPP > H2TPP > H2TMP). The order of reactivity for metalloporphyrins is Zn > Mn > Fe > Co for the same porphyrin ligand. A turnover number (TON) up to 6,000 with selectivity up to 95% was obtained by ClMnTDCPP. In free-base porphyrins and Zn porphyrins, singlet oxygen production is the major route for oxidation, whereas in Mn and Fe porphyrins, two parallel pathways for oxidation products is proposed.

Silver dendritic nanostructures formed at the solid/liquid interface via electroless deposition

Silver dendritic nanostructures and nanoplates were prepared at the solid/liquid interfaces via electroless deposition. Langmuir monolayers of 5,10,15,20-tetra-4-oxy(2-stearic acid) phenyl porphyrin (TSPP) and arachidic acid (AA) were formed at the air/AgNO 3 aqueous solution interface. These nanostructures were produced when carbon-coated copper grids were covered on the Langmuir monolayers at lower (<20 °C) and higher (20–50 °C) temperature, respectively, and the branches are composed of parallel aligned nanobelts with their (110) face parallel to the interface. The formation of the nanostructures should be attributed to the galvanic reduction of Ag + ions by copper, the electronic conductivity of the carbon layer, the templating effect of the Langmuir monolayer, and the non-equilibrium growth and aggregation of silver nanoparticles at the interface. This is a convenient avenue to produce metal nanostructures.

Synchronously synthesizing and immobilizing porphyrins on crosslinked polystyrene microspheres and preliminary study on catalytic activity of supported metalloporphyrins

AbstractA novel method for immobilizing porphyrins as well as metalloporphyrins (MPs) on polymeric supports was found, and it is the way to synchronously synthesize and immobilize porphyrins on polymeric microspheres. By using 4‐hydroxybenzaldehyde (HBA)‐bound crosslinked polystyrene (CPS) microspheres, pyrrole, and benzaldehyde in a solution as co‐reactants and through the Adler's reaction between solid–liquid phases, it was successfully realized to simultaneously synthesize and immobilize phenyl porphyrin (PP) on CPS microspheres, resulting in PP‐supported microspheres PP–CPS. With the same method, substituted PPs, 4‐chlorophenyl porphyrin (CPP) and 4‐nitrophenyl porphyrin (NPP), were also successfully immobilized on CPS microspheres by using substituted benzaldehydes, 4‐chlorobenzaldehyde and 4‐nitrobenzaldehyde, as one reactant in the solution, respectively, and other two porphyrin‐supported microspheres, CPP–CPS and NPP–CPS, were obtained. The effects of various factors on the process of synchronously synthesizing and immobilizing porphyrins on CPS microspheres were mainly studied. Further, the coordination reaction of cobalt salt with PP–CPS as well as CPP–CPS and NPP–CPS was conducted, forming three solid catalysts, CoPP–CPS, CoCPP–CPS, and CoNPP–CPS. The catalytic properties of these catalysts in the catalytic oxidation of ethylbenzene to acetophenone by dioxygen were preliminarily examined. The experimental results indicate that the Adler's reaction between solid–liquid phases, namely the reaction between HBA‐bound CPS microspheres and pyrrole as well as free benzaldehyde or analogs in the solution can favorably be carried out. For this process, the fitting protonic acid catalyst is p‐nitrobenzoic acid and appropriate solvent is dimethyl sulfoxide (DMSO). By comparison, the process of preparing CPP–CPS microspheres is easier to be carried out. The obtained three solid catalysts can effectively catalyze the oxidation of ethylbenzene to acetophenone by dioxygen. In comparison, the catalytic activity of CoNPP–CPS is the highest. Copyright © 2009 John Wiley &amp; Sons, Ltd.

Optical investigations of interaction between zinc tetra phenyl porphyrin and CdSe nanoparticles

Interactions between nanoparticles of zinc tetra phenyl porphyrin (ZnTPP) with CdSe nanoparticles in dimethyl sulphoxide solvent have been investigated. A ZnTPP–CdSe complex was formed which showed substantial changes in the UV–Vis absorption spectra in the presence of CdSe. Fluorescence measurements showed an interesting behavior at low as well as high concentrations of CdSe. When low concentrations of CdSe nanoparticles were added to the ZnTPP nanoparticles solution, besides two fluorescence bands due to ZnTPP nanoparticles, an intense new band appeared. On the other hand at high concentrations of CdSe one of the fluorescence band of ZnTPP at ∼604 nm increased.

Electrochemical Reduction and Voltammetric Determination of Metronidazole Benzoate at Modified Carbon Paste Electrode

A metalloporphyrin incorporated carbon paste sensor has been developed for the determination of metronidazole benzoate (MTZB). Zn(II) complex of 5,10,15,20-tetrakis (3-methoxy-4-hydroxy phenyl) porphyrin (TMHPP) was used as the active material. The MTZB gave a well-defined reduction peak at−0.713 V in 0.1 mol l−1 phosphate buffer solution of pH around 7. Compared with bare carbon paste electrode (CPE), the TMHPP Zn(II) modified electrode significantly enhanced the reduction peak current of MTZB as well as lowered its reduction potential. Under optimum conditions the reduction peak current was proportional to MTZB concentration over the range 1 × 10−3 mol l−1 to 1 × 10−5 mol l−1. The detection limit was found to be 4.36 × 10−6 mol l−1. This sensor has been successfully applied for the determination of MTZB in pharmaceutical formulations and urine samples.

Self-Assembled Nano-Structures of Sandwich-Type Mixed (Phthalocyaninato)(porphyrinato) Rear Earth Complexes. Effect of Porphyrin-Phthalocyanine Ligands on Tuning the Inter-Molecular Interaction

phthalocyanine, porphyrin, sandwich rare earth complex, nanostructure, self-assembly. Abstract. Three novel sandwich-type mixed (phthalocyaninato)(porphyrinato) rear earth complexes, namely Ce(DPP)(Pc)(1), Sm2(DPP)(Pc)2(2) and Sm2(DPP)2(Pc)(3) [Pc = dianion of phthalocyanine, DPP= dianion of 5,15-di(phenyl)porphyrin], have been fabricated into nano-assemblies onto the SiO2 surface by a surface assisted solvent-vapor annealing method. The effect of the number of porphyrin and phthalocyanine ligands on the morphology of self-assembled nanostructures of these double- and triple-decker complexes has been systematically studied. Competition and cooperation between the inter-molecular - interaction, van der Waals, and metal-ligand coordination for different compounds results in nanostructures with different morphology from approximately spherical shape with average size of ~300 nm and ~400 nm for 1 and 2, respectively, nano-rods with aspect ratio (length over width) around 5 for 3, which were characterized by electronic absorption, X-ray diffraction (XRD), and atomic force microscopy (AFM). Electronic absorption spectroscopic results reveal the formation of J-aggregates in the nano-structures and suggest the increasing - interaction in the order of 3, 1, to 2. Examination by XRD reveal that in the nanostructures of compounds 1-3, a dimeric supramolecular structure was formed through an intermolecular - interaction and/or van der Waals between two sandwich-type molecules, which as the building block self-assembles into the target nanostructures.