Synthesis,Optical and Photovoltaic Properties of Porphyrin Dyes

The synthesis and optical absorption of a series of porphyrins, and the photoelectrochemical properties of TiO₂ solar cells sensititized with these porphyrins was investigated. The different types of porphyrins studied are designated by numbers: the reference compound 1 (Zinc(II) 5,15-bis(4-carboxylphenyl)porphyrin), porphyrin substituted with one triarylamine unit 2, and porphyrin substituted with two triarylamine units 3. The UV-Vis absorption spectra reveal that the substitutions result in large redshifts in both the Soret band (～ 60 nm) and the Q bands (～ 125 nm), as well as enhancement of optical absorption. The enhancement is even more pronounced in the long-wavelength region of 575–725 nm, where the absorption of porphyrin 3 is eight times that of porphyrin 1. The photoelectrochemical properties of the porphyrins were also studied by constructing porphyrin-sensitized TiO₂ solar cells. Under standard AM 1.5 sunlight, the porphyrin 1 cell yields a short-circuit current of ～ 1.26 mA/cm², an open-circuit voltage of ～ 0.564 V, and a fill factor of ～ 61%. The incident photon-to-current conversion efficiency is ～ 24% for porphyrin 1 and ～ 5–7% for porphyrins 2 and 3 at the Soret peak.     

Synthesis and Characterization of a Series of Cationic Porphyrins Having Different Steric Effects

Abstract

A series of cationic porphyrins having only different steric effects and their cobalt complexes were synthesized. The cations of these porphyrins are meso-tetrakis(4-N-propylpyridyl)porphyrin (TPPyP⁴⁺), meso-tetrakis(4-N-ethylpyridyl)porphyrin (TEPyP⁴⁺) and meso-tetrakis(4-N-methylpyridyl)porphyrin (TMPyP⁴⁺), respectively. The anions are I^? (water soluble porphyrins) and ClO₄ ^? (organic solvent soluble porphyrins), respectively. The synthetic cationic porphyrins were characterized by elemental analysis, UV-visible absorption spectra, FTIR, MALDI-TOF-MS and ¹H-NMR spectra.     

Reactions of Chelate Complexes with Macrocyclic Ligands. Tetra-tert-butylphthalocyanine

Complexation reactions of tetra-tert-butylphthalocyanine (I) with Cu(II) acetate, acetylacetonate, 8-hydroxyquinolate, glycinate, valinate or dithizonate, as well as with Zn(II), Co(II), and Ni(II) 8-hydroxy-quinolates, valinates, and dithizonates were studied. Unlike porphyrins themselves and porphyrins with planar distortions, compound I was found to form metal phthalocyanines with all indicated chelate salts in common solvents. It was established that compound I exhibits more equalized dependences of the coordination rate on the nature of the salt anion and cation as compared to the majority of the other porphyrins.     

Crystal Structure and Chemical Reactivity of Heme Phenoxide Adducts

Abstract

A simple phenoxide heme compound has been fully structurally characterized for the first time. The crystal structure of a 2,6-dichlorophenoxy Fe(III) 5,10,15,20-tetraphenylporphyrin is reported and compared with the structure of simple aliphatic alkoxy aducts of Fe(III) porphyrins. It is further shown that phenoxy Fe porphyrins can promote regiospecific substitution (cyanation) of the bound phenol ring.     

Two spectral QSPR models of porphyrin macromolecules for chelating heavy metals and different ligands released from industrial solvents: CH2Cl2, CHCl3 and toluene

ABSTRACT

Two simple and reliable correlations are introduced for the prediction of emission and absorption of porphyrins and their derivatives, i.e. metalloporphyrins and ligand coordinated metalloporphyrins. They can be used to sense the extracted precious metals. The proposed models require only simple structural parameters such as the number of carbon, metal and metal-free molecular fragments of desirable porphyrins or their derivatives. Since the proposed models depend on molecular structures of the desired compounds, they can be easily applied for complex molecular structures. Experimental data of 272 porphyrin derivatives were used to derive and test the novel models for the assessment of their emission (Em.) and absorption (Abs.) values in three solvents namely dichloromethane, toluene and chloroform. The values of the coefficients of determination (r ²) for the training set (183 compounds) in dichloromethane and three different test sets, corresponding to the three mentioned solvents, for the emission and absorption correlations were greater than 0.70. The calculated values of the root-mean-square error (RMSE) for the training sets of Em. and Abs. correlations were equal to 7.56 and 4.86 nm, respectively. Further statistical parameters also confirm the high reliability of the new models.     

THE EFFECTS OF PERIPHERAL SUBSTITUENTS ON THE KINETICS OF ZINC ION INCORPORATION AND ACID CATALYZED REMOVAL FROM WATER SOLUBLE SULFONATED PORPHYRINS

Abstract

The kinetics of Zn²⁺ and Zn(OH)⁺ incorporation into and the kinetics of the acid catalyzed removal of Zn(II) from twelve water-soluble, sulfonated derivatives of tetraphenylporphyrin with alkyl or halogen groups in the para, ortho or di-ortho positions were investigated. While the incorporation reactions showed little dependence on porphyrin basicity, the Zn-P (P = porphyrin derivative) acid solvolysis reactions were faster the higher the basicity of the free base (H₂-P) compound. Equilibrium constants for the formation of cadmium porphyrins decreased with an increase in porphyrin basicity. The predeformed tetrakis(4-sulfonatophenyl)-β-octabromo-porphyrin reacted with Zn²⁺ about 10³ times faster than porphyrins of similar basicity. These results indicate how substituents on the phenyl and beta-pyrrole rings influence the solution chemistry of water soluble porphyrins.     

Synthesis of o- and m-Carborane-substituted Porphyrins of the Natural Type

Basing on protoporphyrin IX, its monobenzyl ester, deuteroporphyrin IX, 9-hydroxymethyl-m- and 9-hydroxymethyl-p-carboranes, mono- and dicarborane-containing porphyrins were prepared.     

Meso位单取代卟啉及其配合物的合成、表征和光谱性质

设计合成了一系列新型的meso位N,N-二甲氨基苯基或N-苯基咔唑基单取代卟啉(5a~c)及其锌配合物(6a~c),用高分辨质谱、¹H NMR、紫外-可见光谱及X射线单晶衍射方法等对结构进行了表征;研究了卟啉化合物及其配合物的热稳定性及荧光性质。结果表明,这些卟啉化合物及其锌配合物在400~410 nm之间具有强的吸收且具有很好的热稳定性,荧光量子产率在0.05~0.09;另外还分析了meso位不同取代基对光谱性质的影响。     

NEW LIPOPHILIC BISPOCKET-PORPHYRINS FOR CHEMOTHERAPY OF CANCER (PART I); PREPARATION AND PROPERTIES OF 5,10,15,20-TETRAKIS(3′,5′-DI-t-BUTYLPHENYL) PORPHYRIN METAL COMPLEXES1

Abstract

A series of highly lipophilic bis-pocket porphyrins, 5,10,15,20-tetrakis(3′, 5′-di-t-butylphenyl)porphyrin with five metals (copper(II), nickel(II), zinc(II), cobalt(II), and iron(III)), have been prepared and characterized on the basis of electronic, infrared and ¹H NMR spectra. Although electronic spectra of these porphyrins are substantially the same as their prototype tetraphenylporphyrin complexes of the respective metals, their solubility in common organic solvents such as chloroform, benzene, and hexane is dramatically enhanced.     

Effects of pluronic silica nanoparticles on the photophysical and photodynamic therapy behavior of triphenyl-p-phenoxy benzoic acid metalloporphyrins

5, 10, 15, Triphenyl-20-p-phenoxy benzoic acid porphyrins (P) containing Zn (ZnP), Ga (GaP), and Si (SiP) were synthesized and conjugated to pluronic-silica (PluS) nanoparticles (NPs) where the fluorescence and singlet oxygen generating behavior of the porphyrins were investigated. The highest singlet oxygen quantum yield (Φ_Δ) was obtained for ZnP. When the porphyrins were conjugated to the PluS NPs, the Φ_Δ was quenched and fluorescence was enhanced. The pore size of the NPs upon conjugation decreased from 18.9 nm for PluS NPs to 2.4 nm (for ZnP as an example) as determined by applying the Brunauer–Emmett–Teller method. The porphyrin complexes and their conjugates were tested for their photodynamic therapy (PDT) activity on MCF-7 breast cancer cells. It was found that ZnP and its conjugate showed the highest PDT activity. The p > 0.05 indicated that ZnP is significantly different than GaP and SiP.     

Methoxy-isoporphyrins of water-soluble porphyrins: synthesis,characterization and electrochemical properties

Abstract

Methoxy-isoporphyrins of zinc [5,10,15,20-tetrakis(4-sulfonatophenyl)]porphyrin, ZnTSPP (1a) and zinc [5,10,15,20-tetrakis(4-carboxyphenyl)]porphyrin, ZnTCPP (1b) have been synthesized and characterized using standard spectroscopic techniques (Uv-visible, ¹H NMR) , ESI-mass spectrometry and powder X-ray diffraction studies. The isoporphyrins [5-(methoxy)-5,10,15,20-tetrakis(4-sulfonatophenyl)-5H,15H-porphinato]zinc(II) (2a) and [5-(methoxy)-5,10,15,20-tetrakis(4-carboxyphenyl)-5H,21H-porphinato]zinc(II) (2b) are formed due to nucleophilic attack of the methanol to the zinc porphyrin dication. Ceric ammonium nitrate (CAN) was used to oxidize zinc porphyrin and to form zinc porphyrin dication. The electronic spectra of the isoporphyrin complexes 2a and 2b exhibit an intense peak at near IR region . Electrochemical measurements of the synthesized isoporphyrins showed a typical irreversible reduction peak at lower potential. S-containing nucleophiles, which work as reducing agents, convert the zinc isoporphyrins to their parent porphyrins, which supports the electrochemical observations. Their structural properties have been studied using powder X-ray diffraction. The luminescence properties of isoporphyrins were compared with the parent zinc porphyrins.     

Meso位单取代卟啉及其配合物的合成、表征和光谱性质

设计合成了一系列新型的meso位N,N-二甲氨基苯基或N-苯基咔唑基单取代卟啉（5a~c）及其锌配合物（6a~c）,用高分辨质谱、¹H NMR、紫外-可见光谱及X射线单晶衍射方法等对结构进行了表征;研究了卟啉化合物及其配合物的热稳定性及荧光性质。结果表明,这些卟啉化合物及其锌配合物在400~410 nm之间具有强的吸收且具有很好的热稳定性,荧光量子产率在0.05~0.09;另外还分析了meso位不同取代基对光谱性质的影响。     

Synthesis and dark toxicity of 5-(4-carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato chlorido gallium(III) when conjugated to δ-aminolevulinic acid

5-(4-Carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato chlorido gallium(III) (2) was synthesized and then linked to ethyl ester δ-aminolevulinic acid to form 3. There was no shift in Soret band following conjugation. The fluorescence and singlet oxygen generating behavior of the porphyrins were also investigated. The highest singlet oxygen quantum yield (Φ_Δ) obtained was that of 3. Complexes 2 and 3 as well as metal free 5-(4-carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato showed no dark toxicity on MCF-7 breast cancer cells.     

Some novel manganese(III) porphyrins with catalytic properties

Abstract

A series of manganese(III) porphyrins with 4-methylimidazole have been prepared. These are high-spin complexes having general formula [Mn^III(THMPP)X(4-MeIm)], where THMP?=?5,10,15,20-tetra(4-hydroxy-3-methoxyphenyl)porphine ligand, X?=?Cl^?, Br^?, NCS^?, or N₃^? and 4-MeIm?=?4-methylimidazole. All the complexes have been characterized by UV-visible, FT-IR, ESI-MS spectra, elemental analyses and magnetic susceptibility measurements. These manganese(III) porphyrins oxidize aromatic alcohols to aldehydes. The oxidation reactions have been carried out at room temperature in the presence of oxidants such as NaIO₄, H₂O₂, and NaOCl. The comparative studies proved that NaIO₄ behaves as the most efficient oxidant in these oxidative transformation reactions.     

Highly Sensitive Spectrofluorometric Determination of Nucleic Acid Based on the Aggregation of two Oppositely Charged Kinds of Water-Soluble Porphyrins

Abstract

When cationic 5, 10, 15, 20-tetrakis(4-N-trimethylaminophenyl)porphine (TTMAPP) and anionic 5, 10, 15, 20-tetrakis(4-sulfophenyl)porphine (TSPP) were mixed in aqueous solution, these compounds were rapidly aggregated due mainly to their electrostatic interaction. The fluorescences of both porphyrins were quenched. However, if small amounts of a bulky molecule such as a polymer electrolyte coexisted in this reaction system, the aggregation of TTMAPP and TSPP was inhibited and their fluorescences reappeared. Based on these findings, a new highly sensitive spectrofluorometric determination of nucleic acids (DNA, RNA) was developed. Each calibration curve was linear in the concentration range of 0.03–0.4 μg/ml (DNA) and 0–05–0.6 μg/ml (RNA). Further, the detection limit (S/N = 3) was 0.016 μg/ml for DNA and for RNA, 0.020 μg/ml. The relative standard deviations were DNA: 1.70% and RNA: 1.83% (5 determinations). When the proposed method was applied to the determination of DNA originating from a bacteriophage, the results were satisfactory.     

二硫桥键钴卟啉二聚体的合成与电催化氧还原性能

成功合成了二硫桥键相连的钴卟啉二聚体2Co。通过循环伏安电化学方法测试,在无水二氯甲烷溶剂中,钴卟啉二聚体展示了3个氧化和2个还原峰,表明此钴卟啉二聚体可以稳定多重负/正电荷。详细研究了在酸性条件下的钴卟啉二聚体的电催化氧还原性能。钴卟啉二聚体的电催化氧还原显示了高稳定性和高活性,测得转移电子数为3.5~3.6之间。钴卟啉二聚体的电催化氧还原性能说明通过二硫键对钴卟啉单体二聚化可以提高钴卟啉的电催化氧还原性能。     

KINETIC STUDIES OF THE REDUCTION OF CHLOROMANGANESE PORPHYRIN

Abstract

The reduction of manganese(III) porphyrins by hydrazine (L) was investigated by stopped-flow techniques. The mechanism of the reaction has been proposed based on the experimental results; the relationship between pseudo-first-order rate constants with the concentration of L. Calculated activation parameters showed that the pre-equilibrium step was exothermic and the reduction step endothermic. Substituent effects in the phenyl rings on the two steps have been examined.     

Supramolecular Assemblies of Sulfur- and Selenium- Containing Expanded Porphyrins Mediated Through Noncovalent Interactions

Abstract

Various supramolecular assemblies based on expanded porphyrins building blocks containing sulfur and/or selenium in the core, formed through multiple non-covalent hydrogen bonding interactions are highlighted. Specifically, modified expanded porphyrins such as 22 π sapphyrins, 26 π rubyrins, and 34 π octaphyrins self assemble in solid state through C–H…O, C–H…N, C–H…S, C–H…Se, C–H…π, and C–H…Cl interactions to form dimeric, oligomeric, and three dimensional networks. Furthermore, the supramolecular networks promoted by trapped solvent molecules such as nitrobenzene and bound anions such as chloride or trifluoroacetate through noncovalent interactions will be discussed.     

Coordination compounds of cobalt porphyrins with nitrogen monoxide

Complex formation of NO and the NO ₂ ⁻ ion with cobalt porphyrins bearing various substituents in the porphyrin macrocycle, viz., tetraphenylporphine (1), β-octabromo-meso-tetraphenylporphyrin (2), protoporphyrin IX (3), and 5,10,15,20-tetra(4N-carboxymethylene-pyridyl)porphyrin tetrabromide (4), was studied. The stability constants of the nitrosyl and nitrite extracomplexes in water and in ethanol were determined. Porphyrin 4 forms the most stable extracomplexes. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 715–718, April, 2007.     

Synthesis and mesomorphic behaviour of novel discotic meso‐tetra(3,4,5‐n‐trialkoxybenzoylaminophenyl)porphyrins

Novel porphyrin derivatives with twelve flexible alkyl chains, namely meso‐tetra[4‐(3,4,5‐n‐trialkoxybenzoylamino)phenyl]porphyrins (1a, n = 12; 1b, n = 16) and the zinc complex (2a) were synthesized. The mesomorphic properties were investigated by DSC, WAXD and polarizing optical microscopy; the results showed that 1a and 2a exhibit a pseudo‐hexagonal columnar phase, and 1b a rectangular (Col) phase over a wide temperature range including room temperature.